[jmdotter]

I was thinking of getting a '73-79 GMC and possibly putting a Pontiac 350 in it (I always wanted a Pontiac truck). GMC's were built with the Pontiac engine, so I think it would be appropriate to continue that heritage (rationalization, maybe). Problem is, the '73-79s don't seem to be for sale very often around here in other then POS condition (do to the Northeast salt and winter fun I imagine). Brings me to my question:

Has anyone put a Pontiac V8 into a post-Pontiac engine era ('81) GMC/Chevy truck, and gotten away with it legally (emissions and all))? In the great state of New Jersey? Or even California ('cause if you can do it there, I'm golden )...

Some guy offered to trade me his '87 truck in mint shape for my '50 Ford, and I was wondering if it would be a legal swap. Whether or not I could legally do the swap (305 TPI to Poncho 350) will probably decide the outcome, so any input is welcome.

Thanks!

[Mr6x]

I would think the later trucks with the diesel 350 would make the best candidates. I think the transmission is BOP style and the frame mounts on the truck might be able to be retained. Not sure about what Pontiac motor mounts to use.

[jmdotter]

I think you're right Mr6x, however, I'm more concerned with the legality of the swap; most state laws require you put a same year or newer engine in your vehicle. What I'm thinking of doing is taking a engine last made in '81 and putting it in a later truck, like an '87. I'm more concerned with getting away with it then appeasing the tree huggers, so anybody with experience in doing this in New Jersey feel free to chime in... any tips/tricks to make it look legit?

[RandyW]

Most inspectors wouldn't know the difference if you don't use Pontiac logo stuff.

[Donovan]

aren't the old Diesels exempt making that kind of truck perfoect for this swap? I thought I had heard that.

[Judge Smails]

I may be clueless but I didn't think GM had put Pontiac engines into GMCs since the mid to late '50s?

[jmdotter]

Originally Posted by Judge Smails

I may be clueless but I didn't think GM had put Pontiac engines into GMCs since the mid to late '50s?

True. However, in my mind, GMC's should have continued to use the Pontiac engine, and never have gone to Chevy. Nothing against Chevy, just my opinion that it would have made the GMC line that much more unique and different from the Chevy line-up, and we would have had a fine substitute for a Pontiac truck.

Imagine ordering a GMC step side with a factory 455 to pull your strictly drag car around...

[jmdotter]

Well, I think I've figure out that I can probably get away with it. My mechanic does inspections, and he's a big GM guy. He passed my wagon with the thing leaking exhaust at the block due to snapped exhaust studs, so my guess is I could pull it off. I guess the next thing to research is, can a TBI 305 fuel injection system be mounted and made to work (well) on a small displacement Pontiac.

[RandyW]

Originally Posted by jmdotter

I guess the next thing to research is, can a TBI 305 fuel injection system be mounted and made to work (well) on a small displacement Pontiac.

It'll work fine on any Pontiac.
Check this link; http://www.affordable-fuel-injection...re.php?crn=210

[jmdotter]

Originally Posted by RandyW

It'll work fine on any Pontiac.
Check this link; http://www.affordable-fuel-injection...re.php?crn=210

Thanks!!! I really appreciate that; looks like some cool stuff available. Ahh, the reading begins!

[Stuckinda60s]

I ran a torque-built 400 in an '81 GMC Shortbed with 2.73 gears and a 3-speed. It originally had a 250-6 in it. Even with oversized tires which brought the rear ratio down to around 2.35, it still hauled a 6000# trailer/car load with ease. At speed I could pull all the hills on the interstates in NE PA in high gear. Absolutely unbelievable torque. The mileage was decent, also, running from 11-1/2 to 12-1/2 towing and 19-20, unladen. I even managed to keep the same clutch for 75k miles.

I eventually went to a 3.08 and that brought it back to about an actual 2.70 ratio.

In my opinion, when all things like mileage, reliability and towing ability are considered, the 400 makes just about the best possible towing engine.

I'm currently considering a P350 with slightly lower gears, probably a true 3.08 ratio. Then using an OD automatic. I think this would give really good mileage and still have good towing ability with the advantage of the torque converter.

[Stuckinda60s]

By the way, most states consider vehicles older than 25-years old to be antiques and most are considered exempt from emissions testing.

[ruf455]

I am going to hijack this a bit, what frame mounts/motor mounts did you guys use? I have a 455 ready to go into my Blazer...

[Jeff Walker]

I used the frame/motor mounts from a 73-77 Lemans or Grand Prix in two trucks of mine that are Poncho powered. Also I think the full size Pontiacs started used the same style around 72-73.

[gto1025]

Back in the 70's I installed many 400, 455 pontiacs ond olds 455's in chevy trucks for poeple who wanted to tow. The olds 455 always felt better although I am a pontiac nut. I have a pontiac powered El Camino with a pontiac 400 w/ 4 speed and a shaker hood and trans am extracters on the front fenders, and a 75 grand am dash. I always used the mounts and rad from the doner car, usually a 69 to 73 fullsize car. I would redo the 400 trans with 4x4 tailshaft for 4x4 trucks. The 65 olds, buick and caddy 400 trans had a twin pitch converter and this worked like an overdrive. augie1025@comcast.net Clarence

[poison heart]

Emissions shouldn't be a problem and I don't see any reason for them to pop the hood anyway.

My good friend's dad is trying to get rid of a '74 C20 Chevy long bed with a 454 auto for next to nothing if you'd be interested. I'd take it but I have no use and no room for it.

[78savette]

Here's a Chev. truck with a Pont 400 in it 4 sale on my boat site.

http://forums.screamandfly.com/forum...d.php?t=168428