[JDHolmes]

I picked up a 350 that runs that I'm going to drop in a 58 GMC pickup. There's tons of information here about 400 and 455 but very little about the measly little 350. This motor is a 73-76 block out of a Firebird with, I assume, stock heads. What's possible for reasonable cost to spruce up the performance a bit? Or is it even worth it to do and just run it til it dies and move up?

[Z Code 400]

Heads...You need to get the SCR up from the stock 7.80:1 rating. There are actually quite a few heads out there that will affect this change. IIRC, the '#48' heads are a very popular swap.

I am using 1966 389 (#092) heads on my 350 Pontiac project...Robert

[Ben M.]

I took a 1976 Pontiac 350 with stock heads (7.6:1) and a slightly more aggressive cam than stock and it runs better than any of my other engines. It pulls pretty good for being a throwaway engine. I don't ever see any more than 2600-3000RPM worst case though.

[BVR421]

here is my 2 cents
If its a truck it is as heavier than a stock Firebird and the Pontiac lowend torque Id guess will best a 350sbc. Ace has developed a 383 stroker kit that will add some torque to the P350. Anything you would do to a 400 for power will be the same with a 350 just keep the cam small as in max 068
If this is a gittin to work, haulin to the dump, goin fishin type truck I wouldnt spend a dime on the 350 other than give it a good stock tuneup maybe some cheap summit headers and cheap $15 summit turbo mufflers (those mufflers are very good), its likely to make a more satisfying truck motor left stock than trying to hop it up. The ability to use 87 octane is a huge bonus these days.
How about throwing up a picture of the truck even if its still ugly, I love 58 GMCs!

[Mr. P-Body]

The 48s Robert alludes to are good, alright, but made of pure unobtainium. It's debatable, too, whether or not large valve heads are good for a 350. We're doing one for a '69 Firebird right now and using the 47s. Small valve, small chamber, 9.6:1. With the Comp XE262H, it's a snappy little performer. Performer intake is also quite good on the smaller Pontiacs. Other good 350 heads are 11s and 17s.

In general, all the things that make a 400 good, make a 350 good. The bore/stroke ratio is not as desirable for head flow, so small valve heads work better (IMO). The rod/stroke ratio is the same as 389 and 400, so rev limits are the same.

350 is no "giant killer". It won't beat up on a 350 Chevy at the same level of tune unless some pretty outrageous stuff is done to it. But it IS a torquey and reliable Pontiac V8. Lots of low-end and reasonable efficiency. With a mild cam and a Q-Jet, 350 HP is pretty easy.

Jim

[Z Code 400]

I forgot to mention the small valve heads. Jim is correct that big valves in the small CID engine just aren't necessary.

I am using 1.970" SBC intakes and stock Pontiac 1.600" exhaust valves in my '092' cylinder heads...Robert

[pastry_chef]

Originally Posted by Mr. P-Body

It won't beat up on a 350 Chevy at the same level of tune unless some pretty outrageous stuff is done to it.

Unless your talking gas mileage, It won't ..period!

In a comparison, unless you outlawed using aftermarket heads, a 350 Chev would come darn close to "beating up on" a 383 Pontiac at the "same level of tune".
The more "racey" the same tune, the worse the beating would be.

Here's 383 vs 383, "same level of tune":

http://www.pontiaczone.com/forum/showthread.php?t=15973
462 hp at 6000 rpm - single plane intake

http://www.brodix.com/heads/tonydyno.html
http://www.tonybarkerracingengines.c...NGINETEST.html

568 HP at 6000 RPM - dual plane intake

Cam specs and type are virtually identical

[stu72]

I kind of look at it this way, the 350 is a starting point until something else better can happen. I am having Dave Hillard cut a set of 47's to put on my 350 and see if the rings will stay together. Once this thing lets loose or I come up with more money it's gone. Let's face it the cost is the same to build a 400. Don't get me wrong I will keep the pontiac 350 over switching to a 350sbc if it come down to it. I have done a few sbc cars and trucks and the satisfaction just was not the same as what I am playing with now. Maybe it's because I have grown up but I have always been different and pontiac suits me just fine.

[se428bandit]

Look at the October 2008 issue of HPP,a 1974 SD455 T/A [13.31 @103MPH] and a 1967 400 HO GTO [13.35@105MPH] [both non air cars] took a beating from a 1969 350 HO lemans with A/C [13.01@108MPH].All three cars had exhaust manifolds BUT the lemans had the log type with the SD and 400 HO had the Ram Air type.
What type of power do you want out of the 350,i have had good luck with 067 or 068 camshaft [adv 4 degrees]factory 4 bbl intake.What type of gear is in the truck,if it's a lower gear [3.23 and up] and should run fairly well.

[Mr. P-Body]

Pastry Chef,

For a "race" engine, you are correct. There are simply too many "goodies" for the SBC out there.

You might be surprised, though, how well a pump-gas 350 Pontiac can do with the proper approach. In a heavier car, with similar parameters, at the 400HP level, a 350 Pontiac CAN hold its own against the mouse.

I advise my Chevy customers that I promise not to "be stupid" about their Chevy engines, as long as they promise not to be about the Pontiac. At certain levels, Pontiac is a better engine than SBC. At others, not so much.

You mention a 383 Chev against a 383 Pontiac. That comparison is against a 350 Pontiac block, stroked to 383. Hardly a fair comparison. How about a 400 block, DESTROKED to 383? Different animal! It all depends on how you look at it. And this IS a "Pontiac site". (:-

Jim

[JDHolmes]

Thanks guys, great information. It's going to be my truck/shop truck and won't ever be raced. The rear end is out of a 2nd gen camaro and I just haven't bothered to find out the gearing at present.

Personally, I'd prefer to put the Pontiac in the GMC and would really not consider the SBC unless it just fell into my lap for next to nothing. I think I'll just dump the 350 in it as it is and see how things go. If there's not enough "pep", I'll move on to better heads and other mods. I'll use the money now to build the mopar 440 for the 40 plymouth coupe.

[Z Code 400]

My stock 1975 Pontiac 350 really surprised me, with just headers and 2.5" exhaust!!! I am looking forward to the '092' heads and the 220°/226° @ .050" - 111.5° LSA camshaft.

That should hold me over until my 427 Pontiac is done....Robert

[heff]

everyone that has ridden in my GP has been impressed with the low end torque and how well the engine pulls through all 4 gears up to my 5200rpm redline. like it was said before, it isn't a 400, and it isn't a sbc. but, as long as you don't go crazy with big valves, a huge cam, too much jetting in a quad, they run great. i think as far an introduction into pontiac engine building, the 350 is a good starting point. mainly because to me, it seems it's a big harder to put together one that won't fall on it's face, since it takes a bit more thought piecing one together than some eheads on a 400. it probably won't run like a 400, but it will still impress you.

[TheLastNorell]

My 350 only has an e-brock 600 carb, HEI ignition, headers, and some way too big cam in it and Ive run a 14.3 in my lemans with a 2.73 open diff. Cant wait to see what it will run with the 3.55 posi I bought along with the 650 holley double pumper

[inthuwind]

Hey Ben, do you have the 6S heads on yours? I have the exact motor if so and was wondering the same thing. I was thinking of swapping in a mild cam, but didn't know what was the biggest I could go.

[Ben M.]

Originally Posted by inthuwind

Hey Ben, do you have the 6S heads on yours?

6X-4 heads. I put what essentially amounts to a "stock replacement" cam from CarQuest. The cam was at least 10 years old judging by the markings on the box. The lift was somewhere around 0.410 or so and the stock one was around 0.330. I was told that it matched the RAIII grind, but who knows for sure. All I know is it idles like stock and has plenty of get-up and go.

[TIN TIGR]

im gonna tell you a story..years ago, i had a buddy with a 69 lemans hobby stock car..raced 1/3 mile dirt in petaluma ca..built him a 350 as engine rules dictated 360 or smaller..2 barrel..factory manifolds

ran a decent 350 block,2.11/1.77 valve heads, hyd cam..many years ago, so i forget all the specs..less then 500 lift im sure of..probably around 240-246 at 050..and id say 106-108 ls

he would kill all the chevys out of the turns..they would catch him at the end of the straight as he braked for the turns..tried to get him to shift the car(2 spd) but he just couldnt..cast rods going 6k plus, lap after lap..on the gas, off the gas

his biggest drawback was he couldnt lead a race..he could drive right on your butt for second place, but when he passed ya for first, he would go 2-3 laps then flip the car..

the point is, the pontiac350, in this form, outran the chevy 350's with ease..more torque off the turns, and as much or more speed down the straights..if you're talking a limited class like this, the pontiac kicks chevys a-ss..comparing a callies crank bla bla 383 8000 dollar engine to a hopped up stock headed 383 pontiac is ridiculous..make the chevy run some 441 castings vs a normal pontiac head, and you got a good race..

[Mr. P-Body]

Tin Tgr,

Good points! We've found in the circle track arena, any class where Pontiacs are "legal" and stock manifolding is REQUIRED, Pontiacs DO kick ass. We did one for a man that runs at Dixieland Speedway in Elizabeth City, NC, for the "B-Bomber" class. Stock manifolding, FACTORY hydraulic cam, 500 CFM Holley, max. 406 CID, 62s, Ram Air IV intake, RARE d-port exhaust manifolds (aluminum version), 041 cam, 1.65 rockers (Melling stockers), and the thing was a BEAST. With this setup, it would pull harder off the corner than the small blocks, and pull the entire length of the straights (as opposed to running out of breath at the flag stand like the Chevys). It broke the crank in the 23rd race (we hadn't found the right guy to grind them yet, but that was years ago). It won 19 of the 22 it finished and was in the top 3 in the other 3. The man spent two months in Ecuador during the season and still finished 2nd in points! He has since moved on to other hobbies, but it left an indelible mark on that track! Pontiacs are not very welcome there anymore. Lots of new "rules" to slow them down.

We tried to get a 350 Pontiac approved for the local track's "Charger Division" (now called "Grand Stock"). Since the bore isn't 4.04" and the stroke isn't 3.48", no dice. Can we modify it to meet those requirements? Nope. Not "stock". Stacked deck...

Jim

[Z Code 400]

The 350 Pontiac has a lot of unrealized potential. I like working with the 'underdog' motors every now and then. I am very happy with my 65,000 mile stock Pontiac 350 and looking forward to more upgrades in the near future.

Mr. P-Body,

Our most competitive oval track engine was a 325 (4.155 X 3.00) SBC turning in excess of 8500 on the straights with an 8.14:1 FDR. There wasn't a 383 that could run with us and this was before minimum CID rules were in place.

The 325 pulled so hard and picked up speed so quick it was hard to describe what it was like to drive it. No doubt the 383's put out more overall torque, but our rpm capability, coupled with the steep FDR, created more effective torque.

Out of the corners, you could hear the 383's start climbing up in the rpm range, but our 325 was always there. It was a very unique sound, more like an indy car. We ran that engine 5 seasons on a single rebuild and when we freshened it up, everything looked perfect inside.

The key to longevity in endurance racing is tuning and fuel curves. I've seen so many guys lose the bearings and respond by shimming the oil pump springs, when all along, the real culprit was running way too lean in the upper rpm ranges...Robert

[Z Code 400]

Originally Posted by Mr. P-Body

Tin Tgr, We tried to get a 350 Pontiac approved for the local track's "Charger Division" (now called "Grand Stock"). Since the bore isn't 4.04" and the stroke isn't 3.48", no dice. Can we modify it to meet those requirements? Nope. Not "stock". Stacked deck...Jim

You may remember that NASCAR couldn't handicap the 426 Hemi enough to make the other cars competitive, so they simply outlawed the engine...Robert