New Blazer 1972 - Got Questions ;-)
 

Well, the Blazer is new to me anyway.

OK...I've been reading, using the search and "lurking" here for about a month now.

I just bought a pretty clean 1972 Blazer with a 327 (not sure what year) not too bad on rust but some where it's supposed to be: behind the doors, floor pan.

I did a compression check while it was cold because I wanted to see if that would show me anything about the piston/rings and I pretty much got 120 on all the cylinders except one and that was 110, so that is at least consistent.

I'm sure the readings were low since the engine was cold so I'll do another one this weekend after the engine has warmed up and see how that goes.

So, thinking about a new motor just in case and I wondered what people have done for carb/throttle body options.

I live in Colorado and I will use the truck for trails and hunting so it will have a lot of uphill/downhill orientation but nothing like rock crawling, just steep mountains around here and lots of rocks to bounce over.

Years ago I had a 1972 3/4 ton 4wd that I used in the mountains and it had a habit of either flooding or starving, depending on the situation.

So.....I was thinking of a throttle body or I heard from my mechanic buddy that Holley is supposed to have come out with a new carburetor that is less prone to those problems.

Has anyone had any experience with that new carb?

What have people done as far as trying to solve that issue?

I don't want to re-invent the wheel so I thought I would take advantage of the experience on this website.

OK....my second problem/question for tonight.

I have some rust in the bed (is that what they call it in a blazer?) behind and in front of the fenders.

I looked on LMC and didn't see replacement material for a Blazer.

Will a regular truck bed work to replace the bad areas?

I figured to just torch or grind out the bad parts and weld new patches in place of them unless I can find a replacement bed or something?

Not sure what the normal procedure is there either.

I hate being a newbie....but I suppose everyone gets that distinction at least once huh? ;-)

Thanks for any input....I WILL have more questions as I go.

Oh yea....FYI

Right now we are tearing out the front and rear axles and putting in front/rear dana 60's with cross over steering, 4" lift (any recommendations on the lift?) and 35" tires. Not sure of the gear ratio yet, but probably end up with at least 411 gears and I'm putting in front and rear ARB's too, and a winch on the nose.

Should be a pretty solid trail/hunting truck after that...and the motor.

It ain't gonna happen overnight, but by next hunting season....should be there.

Re: New Blazer 1972 - Got Questions ;-)
 

Welcome to the board, great looking blazer.

Couple answers for ya from my part of the world.

Fuel injection simply works, all the time.
Cross over is good but not necessary with a 4" lift but should be used for 6".
A 6" lift with those 35's might make for a better choice being from the sound of it, your leaning towards actually wheeling it.
(contingent on wheel back spacing etc)

4:11's will be a decent gear for all around driving but not so great for going off road with the 35's and the anemic 1st gear ratio of the 205 t-case.
With that combo you end up with a 1st gear/low crawl ratio of 40:1.

Jump in, ask all the question's you want, they'll get answered whether you like it or not. :) :lol:

Re: New Blazer 1972 - Got Questions ;-)
 

I have replaced most of my bed (tub). Used a floor out of a lwb. Had to cut front and back to fit right, cross members had to be changed at mount locations, replaced drivers bedside with swb bedside. Hope this little bit of info helps. Ther are a lot more guys that know more about this than me, just ask and they will help.

Re: New Blazer 1972 - Got Questions ;-)
 

Gotta agree w/all the above, but rust seemed like that took forever to get rid of. Post up some pics of the A and B posts, it tends to hide in there and the vent boxes

Congrats on your new purchase, and Welcome to the Boards from Philly, Pa. Sweet truck, hope you can weld

Re: New Blazer 1972 - Got Questions ;-)
 

Welcome to the board looks like you have a nice clean blazer to start with.
I replaced my rear floor in my jimmy with a blazer floor I got from a board member hard to find a good floor you have to keep looking and hoping. First try the board members someone mite be able to help you.

Re: New Blazer 1972 - Got Questions ;-)
 

Rolla, MO huh?
I go through there quite a bit, I have inlaws in Nixa (Springfield basically)
Good turkey hunting around there I hear.

OK....I'll have to check for rust in the vent areas. I'm assuming you mean the manual air vents? I haven't seen any rust there yet and I've torn out all the carpet, but I'll take a harder look.

What about POR? (Paint over rust) is that a viable option after a person thinks they have most of the rust cut out?

Gary 70: Are you saying you replaced the entire bed (tub) at one time?

I see there are bolts on both sides and I guess a guy can air chisel the front and rear, then just bolt/weld another one in place?

There is currently a 4" lift on the blazer and the 33's have plenty of room so I figured I could sneak 35's under it.....is that is too much tire for a 4" lift?

I'm excited to have this truck...I've been looking for a clean 1972 blazer for a couple of years and this one I bought from the original owner....that is tough to find! He kept it in pretty good shape.

What about that new Holley carburetor? Anyone tried it yet?

Fuel injection is an expensive mod.....throttle body injection is iffy according to my mechanic buddy.....so I'm still trying to figure that one out.

I'm looking at replacing the 327 with a 350/350 from a local shop here and for now I'm still planning to use the 350TH with it.

Lots of questions.....thanks for the input.

Re: New Blazer 1972 - Got Questions ;-)
 

Okay...no offense intended but all the questions your asking have been addressed and answered somewhere throughout this board, keep using the search function, try using different 'wording' parameters too, it'll result in even more threads for your viewing pleasure.

The quarters unbolt completely aside from there being a small weld between the rear inner bed pillar and the bed floor, plus some spot welds in the lower B-pillar area.

As for the 4" lift, no there's not enough room to have stock fenders/quarters with 35" tires and trying to wheel it.
You'll end up tearing sheet metal.
Trimming is an option to some.
Of course if you have a very stiff suspension, no worries, it won't flex enough to matter but if it's flexy, at some point you'll have contact.

Why is throttle body injection "iffy"?
It's readily available, easy to find parts for and when installed correctly works great.
Best bang for the buck for a poor mans mod IMO.

A winch is a great thing to have, just beware of your approach angle when installing that new bumper to hold it.

Re: New Blazer 1972 - Got Questions ;-)
 

No offense taken.....and I HAVE used the search, been looking at this website for months now.

Call me lazy but if I can't find what I'm searching for in a couple of searches...I quit searching and start asking.

I know it seems redundant to keep answering the same questions over and over again.....and if it bothers you...please don't feel you have to respond.

I appreciate any and all help I can get.....but telling me to use the search feature is not the kind of help I'm looking for. I've already done that.

I have a message board that gets over 10,000 unique IP addresses a day, I deal with "newbies" all the time.....it comes with the territory.

People like me use these forums to get help and some people (like me) get tired of constantly searching and they start asking questions.

If I've come to the wrong forum.....I will quit looking for help here.

Now...back to the subject:

The approach angle is always a concern but with all the room under that bumper the winch can be pushed back and tucked up.

I have a winch/custom bumper on my 1991 F250 and my 1997 Jeep Cherokee and in both cases I have a better approach angle now than I had with factory bumpers.

Thanks for the input on the 4" lift and the 35's....I will certainly take a harder look at that because it affects my gear ratio also.

There is a program that gives me the factory gear ratio equivalent based on the tire size, so once I settle on tire size....I will know which gears to purchase.

With a TH350 I'm just looking for factory ratios because there is no overdrive.

Again....that is why I'm looking for responses....to see what others have done and find out if they are happy with the results.....BEFORE I make any of these modifications.

As for the throttle body.....I'm just regurgitating what my mechanic buddy tells me. He says it's a nightmare to tune at this altitude.....that is all I know right now....and why I'm asking.

Please don't take any of my comments wrong...I'm here looking for answers....I just don't need any search lessons.....I accuse myself of doing that already ;-)

Re: New Blazer 1972 - Got Questions ;-)
 

:agree:

WELCOME..looks like you found a good ole Blazer there!
The last Blazer I had worked great with 4.11 gears & 35" tires.
If it was me, I'd leave the 4" lift on there & run the 35s (use that $ you saved for something else). It should be good depending on the style of tires you go with. For example, Boggers would be more apt to rub/bend front fenders than BFG Mud Terrains because of the outside lugs sticking out.
Also, I like POR! Don't get me wrong the really bad spots should the cut out & replaced. But for those areas with no real structural damage that are just starting to look bad, go for it.

Re: New Blazer 1972 - Got Questions ;-)
 

I have 35" Dunlop Mud Rovers on my Jimmy with 4''s of lift and I go wheelin all the time and I have never had an issue with the tires rubbing. That could be because if you take a actual tape measure to the tires they are actually around 34''. but whatever they use to be one of the cheapest mud tires out there and Sam's had them on the shelf :)

Re: New Blazer 1972 - Got Questions ;-)
 

Cool...I was wanting 35's so I'm glad to hear you guys are using them and they don't rub. It sure seems like there should be room for them.

I was planning on using ProComp Mud Terrains, I have good luck with that tire and it's a decent street tire as well. Plus it has 3 belted sidewalls....most tires only have 2....I like that extra rock protection - mud isn't usually an issue here, they call them the rocky mountains for a reason ;-)

I'm still hung up on that carb/throttle body issue.....not sure what to do there yet.

Re: New Blazer 1972 - Got Questions ;-)
 

No offense taken here either, I was just letting you know there's tons of reading and great info you've not found yet.

The lift amount vs. tire size is always a huge debate every time it comes up and opinions and experiences differ wildly within this board, same goes for gear ratio's.

The phrase 'wheeling' or 'off road' means completely different things to different people, some actually wheel and others are merely web wheelers, it's tough to tell who's got the real experience.

Fact:
A carb will never run as well or get you as far as injection does in off road situations.
It's either ching up for the F.I. or deal with those carburated woes, your choice.

Flame suite on: :devil:

Enjoy the board, it's a great resource.
http://67-72chevytrucks.com/vboard/s...d.php?t=307709
http://67-72chevytrucks.com/vboard/s...d.php?t=307714

Re: New Blazer 1972 - Got Questions ;-)
 

Here are a couple of pictures....one shows the truck flexing pretty good (damn Jeep trails) and the other is on a rock course. Now I do have a stiff ride which helps but this will show you what you question!

http://i280.photobucket.com/albums/k...52434_1384.jpg
http://i280.photobucket.com/albums/k...37062_5611.jpg

Re: New Blazer 1972 - Got Questions ;-)
 

Carb + OffRoad = Q-Jet
For me Holly carbs are for cars and higher RPM applications (even if they say it is built for trucks).
I ran an Edelbrock 1902 Q-jet for years off road on my 350, for a carb had great performance. Did it hesitate and sometimes flood out or slosh..Yes
The Q-jet is hands down THE carb for off-road applications.

Nowa days I run a 454 with Edelbrock MPFI Pro-Flo EFI :metal: WOW! Throttel responce is AMAZING compared to the carb and never do I ever have to worry about flooding out due to hills, bumpy roads or whatever I throw my truck at or into. :metal: :chevy:

With your TH350 Tranny I would step up to 4.56 gears, you will loose Hwy but the torque to the ground will come in handy off road :smoke:

.02c
Burt

Re: New Blazer 1972 - Got Questions ;-)
 

Hey cool, I made the top 20 projects and builds, and another 5 years and it may be done

Not sure what axles your running, but it looks like 1/2 ton. I'd be worried about axle breakage and not having the ability to stop w/35's. Upgrade possible in the future? Good thread on here about 1 ton M/C upgrade on the cheap...

Best way to see the rust in the A post/cowl area is to pull the fenders

Re: New Blazer 1972 - Got Questions ;-)
 

Says he's gonna do D-60's front & rear. :cool:

Re: New Blazer 1972 - Got Questions ;-)
 

Must be CRAFT, or ADD:lol: Thanks for keepin' me tuned in, ol' age sticks

Re: New Blazer 1972 - Got Questions ;-)
 

I just replaced the bed floor not hard to do if you can find one.

Re: New Blazer 1972 - Got Questions ;-)
 

OK...just getting back to a computer....thanks for all the replies.

Thanks for the links vtblazer.....honestly....I've been through every one of those already....several times. Good stuff there.....for sure.

My favorite is the topless thread. I keep going back there looking at roll bars and cages....trying to find what I want.

Just now got back from Wyoming and brought back two Dana 60's from a 1 ton 1986 Chevy ...... they are still in the back of the truck, but I've got 'em and now the fun begins ;-)

When I say I'm going wheeling.....it means that my truck is going into the mountains, it's gonna get bumpy, it's gonna get dirty and more than likely....the winch will come into play at some point....we don't see any pretty trucks where I go.....we all have Colorado pinstriping (scratches for those that don't know what that is ;-)

Not rock crawling mind you.....but rear locker and rock sliders are mandatory.

So.....that being known.....it sounds like I gotta get off the carbs.

I'll start looking into throttle bodies .... full blown fuel injection is more than I really want to invest at this time.....so I might have to use a bandaid for awhile.

Re: New Blazer 1972 - Got Questions ;-)
 

I'll give you a little of my thoughts on 35"s. My first lift on my 69 K20 was a 4" Tuff Country lift with a shackle flip out back. I got 35x12.50x16 Super Swamper SSR's on 16x8" rims with 4.5" backspacing. This truck has 4.56 gears with an SM465 (4 speed manual). I never had this truck crossed up so I can't speak to whether it would have had tire rub, but I would guess it would have. On the street I had absolutely no rubbing. Gear ratio-wise, the highway rpm's are pretty high going 55-60 mph.

I put a 4" lift on my 70 K5 consisting of 4" Superlift front springs and at the same time I swapped in 3/4 ton running gear with 4.10 gears. For the rear lift I had to modify the rear spring perches anyway so I'm using a 2" block and custom spring perches that level out the K5. While I've had my 69 torn apart I put the above 35" Super Swampers on my K5. For whatever reason, these tires on the K5 do rub on the steering components when turning one direction and they are much closer to sheetmetal than when they were on the 69 K20 with a 4" lift. That obviously means the 4" lifts aren't actually the same size so keep that in mind when you buy a lift kit - just because it says it's a 4" lift, that doesn't mean that is what you will end up with. I really like the 35"s with the 4.10 gear ratio - highway speeds are noticeably more rpm friendly. The engine doesn't seem to mind the gear ratio either powerwise.

In the end, I think I would highly recommend a 6" lift with 35"s. I think either 4.10 or 4.56 gear ratio will be a good pick, just really depends on what your going to want to do.

6" lift on a K5 will probably require driveshaft mods, but again, you just don't know for sure until you get into it. I guess your doing Dana 60's anyway so driveshaft mods are probably on the table anyway.

You have a great looking K5 and I hope you'll find this board to be a great asset.

I sometimes find the search function to work really well for what I'm looking for, but other times it can be next to worthless.

Keep us updated on your project's progress.

Re: New Blazer 1972 - Got Questions ;-)
 

Yea, I understand the difference between lifts, but not usually 1" difference and usually on the high side so the lift can "settle in"....gotta let the springs breath a little ;-)

OK....so I'm a newbie.....sheesh....

I go to Wyoming....guy had to go to work so he left the axles on the side of the road, no biggie....it's Wyoming....nobody there to steal them ya know.

So I load them up (with a buddy of mine and we needed two more of us and a monkey to make the job easy....whew those are heavy)

Anyway.....I get them to the 4x4 shop today and I've got one Dana 60 (front) and a 14"....and I "bought" 2 Dana 60's.

I hate being a pilgrum....I have no idea what one looks compared to the other....they coulda sold me any axles....I don't know the difference by looking.

So.....change of plans.....

Dana 60 in the front.....14" in the back.....matched pair ;-)

Still looking at a 4" lift and 35's....and if that ain't enough I can put a 1" block under 'em if I need to....but I prefer not to.

I just don't really want to put it on a 6" lift....I'd prefer to keep it a little lower for that center of gravity thing.....mountains, side hills.....long drops......stuff like that bothers me.

If I can't fit 35's I'll go to 33's before I lift it highter.

I've got some 35's on my Ford that I can put on there and drive for awhile to see how it works......and go from there.

And....still being convinced that I gotta go throttle body.

So....now ..... is it throttle body or TPI (which I just learned tonight means Throttle Port Injection)..... I need to buy a vowel or people gotta start talking in full sentences ;-)

Re: New Blazer 1972 - Got Questions ;-)
 

TPI is Tuned Port Injection.

Go TBI (throttle body) it's cheaper, simpler to install, easier to find and will work just as well for your application.

Another really easy, dependable mod is a serpentine belt set up, well worth putting in.

Feel good about the 14BFF, it's totally on par with the D/60.

Re: New Blazer 1972 - Got Questions ;-)
 

EFi come in two basic "types"
Batch fire = squirts fuel to more than one cylinder at a time, in a 'batch'. = TBI

Sequential Fire = squirts fuel to only the cylinder being fired.

Obviously the SFire is more desirable way to go but does cost more up front to perchase. TPI is prolly the cost effective way to get it. Then there is the rout I took and buy aftermarket MPFI = Multi-Point Fuel Injection = SFire, EDelbrock and Holley are the main players..there are others too.

:mm::mm:

Re: New Blazer 1972 - Got Questions ;-)
 

OK.....still working on the fuel injection but before I do that I'm checking the existing motor.

It's a 327 out of a Camaro (not sure of the year)

I live right at 4,700 feet above sea level so that has to have something to do with the results from a compression check?????

I'm getting 120 psi in all cylinders pretty much....

Hot or cold....doesn't matter....same results either way.

What should I be looking for number wise?

I Googled and what I found says it should be 200 psi and I should be seeing roughly 135-150 for "80%" so does this mean my engine is less than 80% or does the altitude play a part in that number?

Motor feels tight, runs good, doesn't smoke but I hate to get it all put together and then find out that I'm running a weak motor.

Anyone out there that can shed some light on that compression at altitude question????

Re: New Blazer 1972 - Got Questions ;-)
 

I don't know how to factor in altitude but when I did a compression test on my 350 I was getting 170-180 readings except one cylinder was down to 90 so I swapped in a 454 and left the SBC world behind me never to return :metal:
Nothing like a stump pulling low RPM 454 RAT!!
YYYYYYEEEEEEEEHHHHHHHHHHHAAAAAAAAAAAAAAAAAAA!! :metal:
Sorry a little too much :mm: for me today! hahaha

Re: New Blazer 1972 - Got Questions ;-)
 

First off, make sure you have all your plugs out when checking comp. Your Alt. shouldn't make any diff. Don't know where that 200 psi came from. But i'd say more in the range of 175 tops. More important that they be uniform. If you have a low one, give a shot of oil in cyl. crank a few times and check again. if it comes up, it's rings. If not probably a valve. also make sure you get three or four strokes before checking your gauge.

Re: New Blazer 1972 - Got Questions ;-)
 

OK...it's been awhile but here is the news.

120 psi per cylinder is good at this altitude (5000 ft above sea level) according to every mechanic and engine builder that I have talked to and I've spoken to a few of them.

The air is thinner....not as much pressure.

A "good" motor at this altitude would be around 140-150....120 is still a strong motor.

But....I just couldn't help myself and I ended up buying a 383 stroker from one of the mechanics that I was talking to so that pretty much takes away that problem with the 327 ;-)

This engine should be around 370 horses at 5000 rpms with a touch over 400 pounds of torque.....I think that is respectable.

Now I'm thinking I can still run those 35's with the 373 gears behind that TH350 and make it work good enough for both highway and the occasional off-road and if need be....take it in the rough stuff now and then when I go hunting.

The pieces are coming together.....now to make up my mind on the fuel delivery system.....TBI is winning so far......