I currently run a 55 Chevy truck- stock apart from a rebuilt 350 sbc- with headers, intake, 600 holley and a mild 60101 lunati cam and th350. Thing is, i should be getting a running 79 firebird next weekend for the front clip and rear axle, but it also has a 400 pontiac in it. I am considering using this engine too as i read on here some good stuff about them, so i would appreciate some comments from people who have driven both or know a bit about them. The rear axle i will be using from the pontiac is a 3.23:1 posi. The 400 is supposed to be sweet and basically stock but i dont mind doing a few upgrades Comments and views appreciated, Steve.
well since its a chevy a chevy is fine but the 350 is always used i would say go with the pontiac motor it would be a slightly different setup! good luck!
I agree, if it was a GMC I would go with the pontiac for sure but being a chevy I'd keep the SBC, besides the 400 if stock would only be around 7.6:1 comp so for a descent upgrade you would have to get it up around 10.5:1. Thats just my opinion...?
Check the Firebird engine closely. By 79 the 400 engines were just a memory. It's more likely a 301 which is one of the most useless and performance unfriendly engines ever to come out of a GM plant. If it was me I'd stick with the Chevy engine in any case.
Yes I agree probably a 301... BUT if it is a 400 stuff it in te truck. The Chevy purists will love you. LOL, they have there 350s in everything anyway.
Yep, have to decode the motor. 301s are junk, parts motors, lot of parts will go on older motors (HEI, front cover, oil pan). The only thing bigger than a 350 in '79 was a 403 Olds motor. While Pontiacs have the displacement cast right into the block, it's damn near impossible to see in a second-gen. I ended up pulling the intake off my '76 to find out it was a 400. There's lots of Pontiac info out there particularly on the later motors if you google it up.
If its a 400 stuff it in the truck .Will add more pulling power and a lot more lowend.If its a 301 take the motor swimming.and stick with the 350
I doubt the Pontiac is a 400, but if it turns out then put it in the truck. To get any power of the 400 you will need to get some more compression or spend a bunch of money. I had the last of the 455 TransAm's in 76 and can remember after reworking the carb/ignition and putting full length headers and exhaust from a 74 SD TransAm (the car was my first wifes) I took it to PIR (Portland International Raceway) and was turning high 13's through the mufflers/3:23s/street tires and the guys with 77 and up TransAms were turning high 14's and low 15's and couldn't figure what I had done to make the car so fast. The later 400's were pretty much slugs. IMHO
The Pontiac 400 was only available in 4-speed cars in 79. All auto trans cars with the "400" engine were actually Oldsmobile 403's. To ID whether it's an Olds motor look to see if it has an oil-filler tube. To ID the Ponchos look at the casting # on the center exhaust ports-if it has a 6X cast into it it's a 400 Pontiac motor. If it has 01 (I think that's it) it's a 301. The 301 also has funky siamesed intake ports. If it's a 301 don't waste your time. Obviously, there's the possibility that the engine may have been swapped out over the years, so it could be something other than the above. Look here for more Pontiac ID info: http://www.pontiacpower.net/castnum01.html
Leave the Pontiac alone. I wouldn't change anything on your truck if it all runs and goes striaght down the road. I know grafting subframes takes a lot of work and if you'd rather be driving than wrenching, just let the firebird go to someone else. The only Firebirds to come with 400 or 403 (oldsmobile) engines were Trans Ams. Even the Formulas got stuck with the 301 or 305 (chevy). They aren't the best choices for making power. Stick with what you've got. Lowering the stock suspension will probably be easier, it'll still ride like a truck, but that's what it is, so that's what it'll be when you're done. Remeber the K.I.S.S. principle...Keep It Super Simple!
This thread reminded me of an engine swap I did for a customer a few years ago. We pulled a 5.7 diesel out of a 78-79 Monte Carlo and dropped in a mildly warmed up Olds 403 from a Trans Am. I know this is off the topic but the owner of the car was seriously pleased the first time he dropped the hammer on the car when he came to pick it up. Straight forward bolt in swap since the 5.7 diesel was based on an Olds V8.
Wow, Thats a lot of replys with some great views and information. It would be nice to keep the 350 as i built it myself last year and its only done 2500 miles since and it keeps the chevy truck, chevy motor thing going. I would just liked some more power! I shall decide for certain when i get it, test drive it and decode the motor. Thanks for the replys fellas.
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