who swapped to a 3.08 gear and how do you like it ?

[prostreetC-10]

Gee....it seems like a matter of opinion!

One this is for sure...you can't have both. Just weigh the time and $$$ to the gain (if any).

[PanelDeland]

My 250 6 cyl 3 OTT runs just fine at 65-70.I have upgradee to power brakes but haven't checked rpm's with the new tires.I put 255-70-15's on the rear and it seems a lot better but it may just be that new tires helped that much.I think I would like a 3:55 or so ratio to really have the best of both worlds.

[mikajo39]

Have 3.07's in my truck never had a problem with it getting off the line with my old stock 350, she'd actually get up and go pretty good and then she'd hum along on the freeway, I was pretty happy with it

[capev86]

my 72 3/4 ton 2wd burb has a 307 w/ 3 on the tree and 4.56 gears in back....now THAT is lousy on the highway. i want to keep the eclectic trans, but i'd swap in an overdrive trans if it were an automatic. overdrive with 3.73 is gonna be better than a 3.08 and no overdrive....you get the best of both worlds. my dad swapped the rear axle from his 84 suburban 1/2 ton 2wd burb into his current '87 2wd burb a couple years ago. the 87 came from texas where the land is flat as a pancake and up here in maine we have a heavy 71 holiday camper and occassionally haul other stuff, so the 3.73 gears really woke up that 350. with overdrive it goes down the highway great driving solo. a 5 or 5 speed manual would be another way to get lower highway rpm. as for my 72 burb, i want to swap in 3.73 gears (with LSD) so i will still have a little pulling power with that 307, otherwise i'd go with as soft as i could get in a 14 bolt full floater. the tires are taller than on a 1/2 ton so that will lower the rpm's a bit. planning to shove the low mile 406sbc we had in my dad's 84 into my truck in the future. for now i have just swapped out the wires, cap and rotor (ac delco plugs not yet in) and upgraded the stock distributor w/ a petronix electronic ignition conversion. thankfully the 307 is tuned for low end power because it has the same stupid short stroke of a 327....lousy in a truck. i'd have preferred a 305 with a 4 barrel and an rv cam like my dad swapped into his 72 burb (1/2 ton 2wd) back in the 80's when the original 350 wore out. but it runs good and i have that 406 with a 3 barrel and hei. should be a very interesting drive w/ a 3 on the column behind it. i won't have overdrive, but this truck will do occassional heavy towing and so i figured the upgrades i'm doing will be a good compromise!

[Longhorn Man]

I have to agree about these trucks being stable and stopping better than some late models.
The 88 - 99 burbs (and clones) are as common as parking lot gravel, and anyone who has driven one (1500 variety) knows they don't stop for jack. My burb has nothing special on it brake wise. Old rotors and old drims, new calipers and mid grade pads from napa, old crusty shoes out back, 3/4 ton master cylinder and booster, and it'll put you through the windshield if I tried.
workinglonghorn... You tried adjusting your front shoes up lately? My one ton longhorn will lock up the rear before the front, but nothing dramatic. It has manual 4 wheel drums, and they aren't in all that good of shape (lots of the parts can't be found) and it stops pretty good. Nothing to write home about, but good enough for a measly 80 MPH.

[WorkinLonghorn]

Guess I'm getting old! I sure as heck wouldn't want to be going 80 and have some Camry with anti-lock brakes do a panic stop in front of me! I'd slide 1/4 mile while doing a double 360 for extra style points.

[BHyatt]

If that was necessary it would be safe to say you were following too close.

It seems that when people refer to fuel mileage their is a lot of what this sentence started with as in "it seems to get". I have noticed that very few people ever actually check fuel mileage they always assume or go bu feeling. If you are going to make the swap be sure and check actual fuel mileage over 3-4 tanks of fuel to establish a starting fuel mileage. This will give you accurate measurements for future comparison.

This is a fun site to see what many late model vehicles are rated from the factory. It is a good reference for you when you have that friend that is always bragging about how his '93 S-10 4 banger is getting 32 mpg or read the same in that Craigslist advert about the same S-10 with the special Corvette wheel option.

http://www.fueleconomy.gov/feg/findacar.htm

[Legolas894]

Originally Posted by BHyatt

If that was necessary it would be safe to say you were following too close.

It seems that when people refer to fuel mileage their is a lot of what this sentence started with as in "it seems to get". I have noticed that very few people ever actually check fuel mileage they always assume or go bu feeling. If you are going to make the swap be sure and check actual fuel mileage over 3-4 tanks of fuel to establish a starting fuel mileage. This will give you accurate measurements for future comparison.

This is a fun site to see what many late model vehicles are rated from the factory. It is a good reference for you when you have that friend that is always bragging about how his '93 S-10 4 banger is getting 32 mpg or read the same in that Craigslist advert about the same S-10 with the special Corvette wheel option.

http://www.fueleconomy.gov/feg/findacar.htm

I wonder if the odometers on these trucks are all that accurate. My speedometer pulses at low speeds (under 30 MPH). So, does that impact the odometer? Also, my speedometer reads about 6 MPH lower than my GPS does.

I know I didn't buy a truck to get good gas mileage. I use it to haul things....

[capev86]

that's a bunch of hog wash.....why do you need to be driving so fast? these are big heavy trucks w/ v8 engines.....its not just gearing but a factor of mass and aerodynamics......when you go over 60 you really start sucking the go go juice. my dad saw a big difference in fuel mileage between 60 and 65 and that's with overdrive. i like pushing the limit a bit, but even in my very smooth 89 buick lesabre w/ super soft gearing (2.0:1 in overdrive), over 75 just felt excessively irresponsible.

living up here at the bottom of maine i like to occasionally visit boston. as anyone who has been up this way before knows, mass drivers as a whole are absolutely crazy. even in maine people are picking up bad habits. 12 years ago when i first got my drivers licence i could drive 65mph and pass almost every car on I95 and now i have to go 75 just to keep up with the flow. fast driving puts more pollution in the air, wastes gas and increases accident rates exponentially as speed goes up. take it easy and enjoy the ride.....better to get there without incident than get a ticket, or worse, wreck a classic suburban and possibly hurt someone. this gospel lesson (lol) especially applies to towing trailers. take the speed demon attitude to the race track....this is a 29 year old talking!

[attack eagle]

I guess things are different up in the frozen north.

I hate being a rolling obstacle and traffic hazard for every one else on the motorways, and I like keeping up with the flow of traffic, and not getting citations for reckless driving or obstructing traffic.

starting 3 miles from my house, for nearly 320 miles straight east the speed limit is 80... fastest interstate segment in the US of A.

The minimum in the 80 mph zone is either 60 or 65 without being cited for reckless driving, and believe me, it really is dangerous to yourself and others to drive 15-25 UNDER the speed of other traffic. Far more dangerous than simply driving 75-80.
It would probably be like you driving 45-50mph on your local interstate. SO I apologize, I forget that everyone isn;t blessed with 75-80 mph interstate like the Cali to GA run.

Shoot, one block from my house, on the major city street the speed limit is 60... and you better run at least that there too.

Everything I own has to run 80 comfortably, or 75 at minimum. Maybe up north it is different... down here, running 60 max doesn't cut the mustard. That is why we have 75 and 80 mph limits.

[capev86]

taking I95 to florida, there is a nice 70mph stretch in several of the southern states, but its 65 max everywhere else on 95. most roads are 65mph max. i have never heard of an 80mph limit before, except way back when you could do 100 in montana which i believe they did away with. its not safe to be driving so fast....it requires more time to stop and manuever and all that because human reaction time is just only so fast....thats why car insurance is higher if you live in mass. i would be really pissed if i was hauling my trailer out west and the local cops pulled me over for going 60. i'm sorry....but i won't be hitting 75mph with a big trailer behind me, no matter how fast the truck "can" pull it. that's just plain stupid. if i were you i'd atleast keep it under 70 in that 80 zone to save a little gas. i understand wanting to keep up with flow of traffic....but with habits these days, the faster someone else goes because they HAVE to pass you. don't be standing still, but go a bit slower than the competition and perhaps they might feel obliged to slow down too.

[19673ontree]

UPDATE !

I had been hounding a friend of mine to let me have a 3spd manual with overdrive transmission that he had laying in his garage , HE GAVE IT TO ME YESTERDAY !!

I am going to try that and see how it roll's !!!!!!!!!!!!

[ol Curt]

Originally Posted by 19673ontree

UPDATE !

I had been hounding a friend of mine to let me have a 3spd manual with overdrive transmission that he had laying in his garage , HE GAVE IT TO ME YESTERDAY !!

I am going to try that and see how it roll's !!!!!!!!!!!!

I would be REALLY interested in knowing how difficult it is to put that in and how it works. I don't want to give up my three on the tree but pushing that six at 2800 can't be good for it. I don't care to run 80, but would like to do 65.

[attack eagle]

<<<APOLOGIES TO ALL FOR ANY OFFENSE>>>

I guess I sounded a bit of a pompus anus, had a bad day.

I had no idea anyone still had speed limits UNDER 70 mph in the US of A. They have been 70 or more for the last decade or more in MS LA and texas, and 75 in NM and AZ. Defacto 75 in LA and MS.


interesting that up north they still have slow speed limits, assuming because of being principally in congested urban areas and consistently poor weather.


I usually leave my house about 5:30 am, by the time i get into the 80 mph zone 20 minutes later, it is light enough to do a legal 80, and if I run the speed limit or 2 over all 1200+ miles I can just make it to 'grandpa's' house before the sun sets.

vs
2 x 11 hour days of driving... + the extra cost of 4 people.

I'll give up one mpg (or two or even 5) for that!!!

if a 3.07 means my future burb can run 75 comfortably, I wouldn't hesitate. i don;t think I can be so lucky though.

I did 17mpg @ 70 in a 93 Dodge Club Cab Ram HD150, which had a 5.9 Magnum MPFi, NV4500 (so 27% OD), on a 3.23 rear gear with a 31" tall tire.
It had about the same aero as any other 1972 design, but that gearing was still about 10% taller than a 3.07 on a 29" before factoring in the OD trans.


And Apologies for dragging this so OT>

[Longhorn Man]

the comment above about the weight of the trucks is wrong, plain and simple.
A typical midsized car weighs more than 67 - 72 1/2 ton trucks. mustang weighs in at over 4000 pounds.
You can poke along under the speed limit, but get the heck out of the way, and look into your speed minimum laws.
Or maybe just stay off the freeway so you are out of the way of others.

[WorkinLonghorn]

In Calif. there is no minimun. All big trucks and anything pulling a trailer is limited to 55 so it's no problem to stay to the right and go 55-60.
My 3.73 diff will have my engine spinning something like 3300 RPM at 80 and the gas mileage will suck and the engine life may suffer.
You guys that think there is a need to haul A around at 80 in a vehicle with no shoulder belt,no air-bags,no crumple-zones, a steel dash etc,in a truck with by design does not have good braking characteristics (60-40 weight distribution at best), have at it,
.
Personally I am cheap and have better uses for my $.

[texanidiot25]

Originally Posted by Longhorn Man

the comment above about the weight of the trucks is wrong, plain and simple.
A typical midsized car weighs more than 67 - 72 1/2 ton trucks. mustang weighs in at over 4000 pounds.
You can poke along under the speed limit, but get the heck out of the way, and look into your speed minimum laws.
Or maybe just stay off the freeway so you are out of the way of others.

Mustangs are 3500 lbs... It's that fat ass Challenger that's 4000+ lbs.

[texanidiot25]

Get a junk set of wheels and put taller tires on. With 31" tires, and a TH350 I now can do 75 mph at 2900-3000 rpm. Haven't had the GPS on, but 80 comes at maybe 3300 or so RPM. Haven't thought to calculate the rear end ratio yet, but with a TH350, you can assume it's high up. But with the old 235/75? rear, I could only do 65 at 3000 rpm, so the difference is big.

[71meangreenc10]

I gotta add onto Longhorn Mans comment,

Ive been moving my trucks across the great USA and was curious about my truck weight for my trailer.

the long bed empty was 4k flat, on the scale. They aint that heavy....but not to areo dynamic. Havent weighed the burb yet. Shorty has got to be in the 3's.

but to add to the thread, I have changed my shorty from 3.73 to 3.07myself and love it. Have a 3 speed manual.

Smitty

[Longhorn Man]

i know the 2005 stang (fully loaded) that we had to weigh for a customer at work came in a tad over 4000 pounds. This was a cat certified scale.

[19673ontree]

as for all this stuff about not feeling safe in our truck's at 80 mph I don't think like that at all , I just wanted the engine rpm's lower at the higher speed's , as far as it bothering me to go 80 mph in my truck IT DON'T !

as far as weight a 1967 to 1972 shortbed C10 (2WD) they weigh 3600 lbs
it says so in the owner's manual , 4x4's and 3/4 ton's weigh more ,

[prostreetC-10]

What is "hog wash"????? lol

My truck weighs 4K with me in it and a BBC.

Glad you clarified the mustang thing. I have a 67 Fastback and that little turd only weighs 2950! Probably one reason why ford made the front suspension out of recycled pop cans!

I used to not want my wife to pull our horse trailer with our Toyota Sequoia. I wanted her to use my old 3/4 cuz it's more stout. Then I drove the Sequoia across the scales and found out it weighed 6,000lbs!!!!! She now only uses the Sequoia.....

[faribran]

19673ontree, i have some 3 spd o/d info if you need it..
Just put one of these in my 67.. i like. havent driven it much.. but seems to work well.

[hensonjd]

i just read through all of this and found some good info. But I never knew that texas was flat as a pancake? The Texas I was raised in, east texas, is very much hilly. It wears me out running coons at night. lol

[ol Curt]

Originally Posted by faribran

19673ontree, i have some 3 spd o/d info if you need it..
Just put one of these in my 67.. i like. havent driven it much.. but seems to work well.

I would like the info if you would share.

Thanks!!