My Project Truck

[FLOutlander]

Greetings,

This post will be kinda long, so bear with me

Back in 1982, my dad bought a brand new Chevy Scottsdale 1/2 ton pick-up. It's 2WD, and came with a 305 V-8 and automatic tranny. I'm not sure if it's a TH350 or TH400.

Since then, the tranny has been rebuilt twice, back to factory specs. No shift kits or anything. The origional 305 was rebuilt once, then was replaced with a 350 that came out of a box van. Not sure what year, but the mechanic told us that this particular 350 had a factory "Towing Cam" in it. Other than that, it's pretty basic. Rochester Carb, stock exhaust manifolds, stock everything.

My dad passed away in 2005, leaving me the truck. He always wanted to restore the truck. Not over-the-top restoration, he never wanted to make it a SHow Truck or anything, but he wanted it to run like new and keep it in the family. He never got a chance to, so I'd like to do it for him now. Here are my plans.

I want to do all the work myself. The mashining I will leave to a reputable shop. But I will be doing all the wrenching. I'd like to rebuild the 350, and make it slightly better than stock. I'm not looking for additional horsepower, but rather reliable factory-like horsepower.

How can I determine what year this 350 is? Also, other than taking it apart, is there a way to see if it's a 4-bolt main or 2-bolt main?

The Rochester Quadrajet has to be replaced. I've personallt rebuilt it twice and it's time to retire. I'd like to move away from the Quadrajet entirely, so what type of carb should I use to replace it that will allow factory specified power output? I think the Quadrajets are something like 750 or even 780cfm. Someone once told me that a Holly or Edelbrock 4-barrel in the 600-650cfm range would be a great replacement. Is this true? Also, what type of carb do I need? I look trough catalogs and see things like vacuum secondaries, mechanical choke, electric choke etc. How do I know which one I will need?

Being an '82, this truck has HEI ignition. About a year ago, I replaced the entire distributor, cap, rotor, and wires with brand new items. Just FYI.

On to the transmission....

As mentioned earlier, I don't know wether it's the TH350 or TH400. How can I find out? This tranny needs to be rebuilt. Is this something I can do myself or will that require some mashining work like an engine does? While I'm in there, I'd like to install a mild shift kit and an auxillary trans-cooler for longevity.

On to the rear axle....

How do I determine what type of gears I have in there? 2.73, 3.23....is there a way to tell? I'd like to install a Posi back there but keep the gears as close to stock as possible. Rear axle seals are shot too so those will be replaced at that time as well.

Other things...

Eventhough this is a 2WD truck, I like to make room for some larger tires. My dad always wanted to lift it a little. Do they make 3-inch body lifts for 2WD trucks? What about 3-4 inch suspension lifts? Just curious.

Aside from all of that, I'd like your opinion on what to do to the engine/tranny to get factory-like power but perhaps some better gas mileage. I'll top things off with a K&N filter, but what else can be done to increase mileage?

Any and all serious help is greatly appritiated. I'm not in a hurry to get this done. It can take a year or two, I don't care. The truck is in a barn, out of the weather.

Kind regards,
Axel

PS: One more thing. Does anyone know what kind of horsepower and torque I should expect at the rear wheels with a stock 350 like mine? Also, when I have the block at the mashine shop, will they bore it larger than stock? If so it will increase the c.i.d. of the engine. Right?

[68GMC454]

sounds like a good project...glad to hear the history on the truck,,which will make it even better when its rebuilt....more than likely the tranny should be a 350 turbo..guessing on it, but since it had the 305,,that should be the one in it...they shouldnt have to bore the engine out unless it is in bad shape or you want it bored out...since you are doing the block,,might as well have the heads done to,,or switch out to a better flowing head,,and have the intake ported to match the heads...hope im rigth on the technical words here..
any pics of the truck
billy

[watahyahknow]

How can I determine what year this 350 is? Also, other than taking it apart, is there a way to see if it's a 4-bolt main or 2-bolt main?

there are websites and books available that alows you to find out year and stuff from the serialnumbers stamped on the block

The Rochester Quadrajet has to be replaced. I've personallt rebuilt it twice and it's time to retire. I'd like to move away from the Quadrajet entirely, so what type of carb should I use to replace it that will allow factory specified power output? I think the Quadrajets are something like 750 or even 780cfm. Someone once told me that a Holly or Edelbrock 4-barrel in the 600-650cfm range would be a great replacement. Is this true? Also, what type of carb do I need? I look trough catalogs and see things like vacuum secondaries, mechanical choke, electric choke etc. How do I know which one I will need?

talk to a machineshop about that one , i like the demon carbs myself

As mentioned earlier, I don't know wether it's the TH350 or TH400. How can I find out? This tranny needs to be rebuilt. Is this something I can do myself or will that require some mashining work like an engine does? While I'm in there, I'd like to install a mild shift kit and an auxillary trans-cooler for longevity.

i is possible to rebuild it yourself but i advise against it , its not realy pricy to have a rebuild done in the states and you get a waranty for IF things go wrong

On to the rear axle....

How do I determine what type of gears I have in there? 2.73, 3.23....is there a way to tell? I'd like to install a Posi back there but keep the gears as close to stock as possible. Rear axle seals are shot too so those will be replaced at that time as well.

eeh something about lifting one reartire and look at the driveshaft rotations per one rotation of the wheel there websites explaining it

Other things...

Eventhough this is a 2WD truck, I like to make room for some larger tires. My dad always wanted to lift it a little. Do they make 3-inch body lifts for 2WD trucks? What about 3-4 inch suspension lifts? Just curious.

it possible to make youre own , ive seen hockypucs being used for that drill a hole in the middle and use longer bolts

Aside from all of that, I'd like your opinion on what to do to the engine/tranny to get factory-like power but perhaps some better gas mileage. I'll top things off with a K&N filter, but what else can be done to increase mileage?

maibe convert the engine to a TBI system (electronic fuelinjection )

[FLOutlander]

Thanks for the input, guys. Did some more research today...

How's this for increasing fuel economy....

Edelbrock Performer Intake, Performer Cam, and Performer 650 Carb. Take the heads to a shop for thorough cleaning, valve job and inspection. Take the block to the shop for cleaning, new freeze plugs, and check for deck flatness. Mill and/or bore out as needed, little as possible. Reassemble engine with all new gaskets, seals, etc. Utilize K&N Air Filter, MSD Ignition, Synthetic fluids thoughout, ceramic coated headers, dual exhaust. Flex fan and new accessories like Powersteering pump, Alt, waterpump...they're all long overdue lol. CLutch van too.

Transmission...I'd REALLY like to rebuild it myself. Not as a money saver, but as a learning experience. Still undecided. Install B&M Shift Kit...but which stage? Street/Strip, RV/Towing???

Rear End....I'm 99% sure that the truck has 3.08 gears. I'm either keeping these or swapping them for a set of 2.73 in order to maximize fuel economy. Good idea? I don't need a truck that jumps off the line...but I don't want it to bog down either, yanno?I just wanna do everything I can to maximize fuel economy without going to TBI.

[Captkaos]

Originally Posted by FLOutlander

How can I determine what year this 350 is?

Get the numbers of the block and look them up here:
http://www.nastyz28.com/sbchevy/sblock.html

Also, other than taking it apart, is there a way to see if it's a 4-bolt main or 2-bolt main?

If it is listed as both on the info above, the only way to tell is to pull the pan. It isn't a big deal if it isn't a 4bolt, They aren't that significantly stronger especially for what you are dealing with.

I think the Quadrajets are something like 750 or even 780cfm. Someone once told me that a Holly or Edelbrock 4-barrel in the 600-650cfm range would be a great replacement. Is this true?

Q-jets are Vacuum operated. The engine pulls in what it needs. I personally would put a new Q-jet back on it. If I couldn't chose that I would go with and Edelbrock.

Also, what type of carb do I need? I look trough catalogs and see things like vacuum secondaries, mechanical choke, electric choke etc. How do I know which one I will need?

Again, it orginally had a Vacuum secondary carb with a mechanical choke. I would still get a vaccuum secondary and use the same choke setup. (just me)

Being an '82, this truck has HEI ignition. About a year ago, I replaced the entire distributor, cap, rotor, and wires with brand new items. Just FYI.

It being an '82 and 2WD in only came with a 305, therefore it had the ESC (electronic Spark Control).

As mentioned earlier, I don't know wether it's the TH350 or TH400. How can I find out?

Compare the trans pan to this:

Is this something I can do myself or will that require some mashining work like an engine does?

It is like building a motor, it will require some specialized tools. Check this link for the books: http://www.atsg.biz/cgi-bin/shopper....26pricecode%3D
If you do rebuild it make sure it has all the updates in it. '82 was the first and worst year of the 700R4, so it is no suprise that is has be rebuild a few times...

How do I determine what type of gears I have in there? 2.73, 3.23....is there a way to tell?

Is the RPO code list still in the glove box? It may be listed there. It is most likely going to be 3.08 unless it was special ordered with something else. Otherwise you can change the fluid (since it probably could use it) and check the gear numbers stamped on the ring gear.

Do they make 3-inch body lifts for 2WD trucks? What about 3-4 inch suspension lifts? Just curious.

http://www.fabtechmotorsports.com/html/home.html makes a 3" spring lift for these. http://www.dogsofdesign.com/fabtechp...alog/Chevy.pdf

Does anyone know what kind of horsepower and torque I should expect at the rear wheels with a stock 350 like mine?

165hp and 240ft/lbs from a stock '82 305. The 350's in the burbs and 4x4s in '82 had 185hp and 275ft/lbs

Also, when I have the block at the mashine shop, will they bore it larger than stock? If so it will increase the c.i.d. of the engine. Right?

Only if it needs overboring. It will incread the displacement, but not enough to make a significant change.

Rear End....I'm 99% sure that the truck has 3.08 gears. I'm either keeping these or swapping them for a set of 2.73 in order to maximize fuel economy. Good idea?

If you want to maximize enconomy you are going the wrong way. I would either stick with what you have or move up no more than 3.42.

Edelbrock Performer Intake, Performer Cam, and Performer 650 Carb.

Sounds like a good plan to me.

[FLOutlander]

Hey man, thanks for your input, I really appritiate it.

Are you sure about the gears, though? I thought that numericly higher gears mean that the engine has to turn more to produce one turn on the wheels. So theoreticly, an engine turning a set of 2.73's would have to turn fewer times than an engine running a set of 3.42's. Maybe I'm just confused?

[project 84]

sound like fun i have a project of my own. so i wish all the best of luck on the project

[Captkaos]

Originally Posted by FLOutlander

Hey man, thanks for your input, I really appritiate it.

Are you sure about the gears, though? I thought that numericly higher gears mean that the engine has to turn more to produce one turn on the wheels. So theoreticly, an engine turning a set of 2.73's would have to turn fewer times than an engine running a set of 3.42's. Maybe I'm just confused?

With overdrive, the truck is will be "searching" for gears. My '87 had 2.73's and it got 21.8mpg on the last trip, but it is barely turning. On small hills and inclines it kept jumping down to 3rd, ALOT! If I had a little more gear it would have been better.

In addition, the difference between 2.73 and 3.08 gears is minimal for the $300 cost of setting up a new gearset.

Example with 3.08 gears and 29" tall tires (235/75/15 -stock) and a 700R4 the RPMs at 60mph in OD is 1499rpm.
If you change to 2.73 gears only the RPMs at 60mph is 1329rpm.
If you change to 3.23 gears only the RPMs at 60mph is 1572 rpm.
If you change to 3.42 gears only the RPMs at 60mph is 1665rpm.

[FLOutlander]

Yeah ok, that makes sense. Like the engine is bogged down too low to move the truck. However, my truck has a TH350, so no overdrive. Would 2.73 gears still be wrong?

[Captkaos]

Originally Posted by FLOutlander

Yeah ok, that makes sense. Like the engine is bogged down too low to move the truck. However, my truck has a TH350, so no overdrive. Would 2.73 gears still be wrong?

I personally wouldn't change from 3.08 to 2.73. You aren't going to lower your rpms by more than 150 with that kind of change. I suggest leaving it alone.

[piecesparts]

Originally Posted by Captkaos

With overdrive, the truck is will be "searching" for gears. My '87 had 2.73's and it got 21.8mpg on the last trip, but it is barely turning. On small hills and inclines it kept jumping down to 3rd, ALOT! If I had a little more gear it would have been better.

In addition, the difference between 2.73 and 3.08 gears is minimal for the $300 cost of setting up a new gearset.

Example with 3.08 gears and 29" tall tires (235/75/15 -stock) and a 700R4 the RPMs at 60mph in OD is 1499rpm.
If you change to 2.73 gears only the RPMs at 60mph is 1329rpm.
If you change to 3.23 gears only the RPMs at 60mph is 1572 rpm.
If you change to 3.42 gears only the RPMs at 60mph is 1665rpm.

For what you want, you need to calculate the size of tire that you are running and work your plans towards a rear end gearing that gives you the optimim RPMs for that motor. I try to keep my engines around the 2100 to 2500 RPM mark. That is what seems to get me the best mileage, good performance in the hills, and the cruise works the best. EXAMPLE: My son's truck had a set of 3.08 gears and after a change to an OD tranny it ran down the highway at 70 MPH at 1900 RPM, that should be great for gas mileage, but he got 11.5 MPG and that was due to having to work the motor to go up and down hills. There is a point of going to far in what is thought to be the GOOD direction. We put a 3.73 Posi unit under the truck and picked up approximately 3 MPG and the truck runs strong on the street. I would recommend a 3.42 gearing for you and then look at what tranny you want.

As for your tranny, I am betting that you have a 350C tranny in that truck. A 350C is a TH350 tranny with a lock up convertor. Those trannys worked well for the times, but they had a smaller output shaft on them compared to the standard TH350. trannys. They are recognized by the TH350 tranny pan and an electrical plug on the driver's side for the lock up unit. I upgraded my trucks to 700R4s to get away from the higher RPMs.

The idea that you proposed for the motor is great, BUT consider the use of a fan clutch with the fan. That will give less drag on the motor and the water pump wear will be less. The flex fans are great for cooling, but will not reduce drag as much as the clutch unit will.

Look at the thought that the motor could be either a two bolt or four bolt and you will truly know when the pan is off. No matter what; the pan is going to come off, RIGHT? So wait until then. As for what you want to do a two bolt will support you for a long time. The four bolt is desirable to the guys that are beating the motor mercilessly. The street guy can hotrod a two bolt without any problem. Get a good set of heads, like DART II Sportsmens or step up to a later GM Vortec head and intake manifold, to get a good horsepower boost. Combined with a moderate cam upgrade, the engine will not only give you a street runner, but better mileage with the smoother performance.

Look for a good set of long tube headers, open dual exhaust, and keep the idea of maximum air in and exhaust out working for you. Look at the timing of the motor closely and set itso that it is adjusted with the carbs settings for the best advance and cruising settings. The timing is important and so is setting the fuel mixture for economy.

[FLOutlander]

Hey all,

I've decided to try and upload some pics of my truck for your viewing pleasure. Please remember, this is a work in progress...slow progress

1982 Chevrolet C-10 Scottsdale

[watahyahknow]

maibe its a better idea to mount a overdrive trans then that way you still have power when pulling away from a stoplight and run more miles per gallon on the longer stretches , agreed the trans is not so strong as a 350 or 400 but behind a near stock small block it schould hold up fine

[gflo383]

im new here, but have done a gear swap in my camaro, i would suggest either leaving the gears alone and going with a th700R4, or even go with a 3.42 gear and the OD auto.

the 700 has had alot of "bad talk" although 82 wasnt the best year for them, 87 had a few upgrades, and finding a usable 87+ 700R4 to rebuild wouldnt be all that hard nor expensive. i ran many mnay 11 second 1/4 mile runs with a mildly built 700R4, fresh rebuild, clutch pack kit, a stock replcacement converter, a stage 2 B&M shift kit and a corvette servo. (out the door about $900) it shifted hard everytime, and in fact its now in a friends 92 camaro as i opted for the 6 speed manual.

the amount of money you MIGHT save from going to a very low gear vs the disappointment in acceleration isnt worth it imo.

Also, call around to local trusted trans shops and ask them an amount for an off the shelf rebuild 700R4 for an 87 C10. the bellhousing is the same, and like i said most of the changes were simply upgrades.

good luck with whatever you do!

Joe G

[84 400]

Wow great project you got there. If it were me and i wanted some better millage i would swap the th350 out for the 700R4 OD tranny. If i rember right they are almost or are a direct swap but you need the 700r4 cross member. As for the carb i personally like Edelbrock. I find parts plentiful and them easy to tune and re jet. I have the thunder avs 650cf carb and a preformer II intake on my SB 400 and love how they work. For fuel millage i would suggest a mild cam and some better flowing heads. Semms like your on the right track for a nice truck. Also on the carbs you can get almost any CFM you want and i would talk to the shop doing your motor work to get an idea of the idea CFm. When building a motor it is all about making sure the parts work together. Also there is a place that you ca get a Q jet from that will build them however you want. I forget the name but some board mebers really like there Qjets. Have fun with it and it should come out to be a nice truck when done. As for the Lift there is a company that makes lift coils for the front and then you could do blocks in the back. Oh and i would suggest ordering a Catolog from Lmc truck cause they have some info in them and a good amount of REpo parts.

Have fun

[BowTieOgre]

If you are looking for a trans or carb hit up the swap meet in Moultrie GA the beginning of February. I saw a vendor last time that had tons of carbs all brand new and shiny.

[FLOutlander]

Awesome. Thanks for all the replies, guys! I'm going to look into a TH700R4 tranny. I'll have it rebuilt with a mild shift kit, stock converter, and a better-than-stock tranny cooler. What do you guys think about the aftermarket external transmission fluid filters? They look like an engine oil filter but they're for transmission fluid and include a magnet to trap metalic particals. It's listed as trapping everything down to 4 microns. Go with it?

If the 700R4 works out, I'll change the rear end gears out to 3.42's. I know this truck is 2WD, but I'm going to lift it a few inches...enough to fit a set of 33x12.50's. Should I go with a Limited SLip or can I go with a Posi? My brothers' 92 Dakota 4x4 has a posi rear end and I love it!

[Captkaos]

I would go with an external cooler on the 700R4, heat is a trans killer.
A limited slip is a posi.

[FLOutlander]

OK, I did some more research today while tinkering with the truck. First off, I took off the drivers' side valve cover to take a peek at the head casting number. Came up with 3988998 and a date stamp of E 7 75. So it was cast on May 7th, 1975. I looked up the casting number and can't find a match, so I don't know any more than I did yesterday. I can't see the engine block casting number untill I get the engine out of the truck....not sure when I can do that, though.

Second, I looked over the RPO Codes list in the truck. For the rear end it says "GQ1 Rear Axle Standard" Went online and looked over many RPO Code Lists and came up with "Rear Axle-Standard". So I STILL don't know what ratio I have back there. There is no stamp or tag on the rear end. All I know is that it's a 10 bolt. But I don't know what spline or what gear ratio...or the diameter of the gear set. I guess that'll have to wait till I can pull all that apart.

[84 400]

Looks like an awsome project. wish i could be more help with the rear end.

[watahyahknow]

it looks kindahlike my truck at the moment only without the clownmobile add ons the previous owner put om my truck , got it moved last weekend to my storage so it can dry out untill i have the cash to work on it

[FLOutlander]

Ok, good news! I ran into a friend today that I hadn't seen in a long while. Turns out he's building a Mud-Bog truck using an '89 Silverado. He said I could have the TH700R4 that the truck came with!!!! FOR FREE!!!!!!!!!!!!!!! I'm going to talk to him more in a few days, and I'll ask him some more questions. I should be able to get the crossmember and shifter assembly as well, since he'll be using either a TH350 or 400. Anyone know how much(ballpark) a rebuild + O.E. Torque Converter might be for a TH700? Just curious.

[watahyahknow]

Originally Posted by FLOutlander

Ok, good news! I ran into a friend today that I hadn't seen in a long while. Turns out he's building a Mud-Bog truck using an '89 Silverado. He said I could have the TH700R4 that the truck came with!!!! FOR FREE!!!!!!!!!!!!!!! I'm going to talk to him more in a few days, and I'll ask him some more questions. I should be able to get the crossmember and shifter assembly as well, since he'll be using either a TH350 or 400. Anyone know how much(ballpark) a rebuild + O.E. Torque Converter might be for a TH700? Just curious.

that is good news indeed , have him trow the driveshaft in too , from wat i heared its longer/shorter than the one for a 350 or 400 im not sure
http://www.artcarr.com/storm.cfm?fun...&Category3=682 torque converters and prices galore go check it out for youreself

[84 400]

That is good news. as for rebuilds do you want the kit or send it out? if sent out it really varies from place to pace.

[gflo383]

is the 700R4 from a 2wd 89 or 4x4?

for the rear end gear, a simple and "somehwhat" accurate way of finding out what geras you have. jack up the rear, spin the drive shaft and count howmany revolutions in comparison to the rear tire. for example 3 1/4 turns would most likely be a 3.23 gear. 3 1/2 turns would be a 3.42 etc. when i was 16 this is how i discovered the gear ratio in my camaro, it works!

as for the ring gear dia. i think its an 8.5" 10 bolt... not possitive though.

also, for a complete rebuild on that 700R4 i would say anywhere from 800-1200 would get it done.