Best Pontiac Powered Stockers

[Billy Nees]

Originally Posted by oldskool

I assume that anyone who has seriously raced one has blown some up.

That would be a mild understatement!

[oldskool]

Maybe Billy can help with this one.

Are there any 350 or larger 2-barrel Pontiac combos that might be competitive, or at least might not be too hard to make run under the index ?

I don't personally know of any 2-barrel Pontiac Stockers.

I'll look up some specs for some 2-barrel Pontiac engines & see what turns up.

Wow ! Apparently VERY few have ever tried to run a Pontiac 2-barrel engine. For the early years they were just rated whatever Pontiac had 'em rated. The only factors I see that were changed were for the '73 & '74 350. It changed to 210hp, in 2002. Maybe somebody tried this combo & asked for a reduction, & got it. From what I see, those are the only years you'd have a chance. The factors for the early 350's were more than for a '77 400 4-barrel engine, at 265hp. And the 400 2-barrel factors were even higher, at 290hp. Those 290hp engines only came in big cars.

http://www.classracerinfo.com/Engine...5&MAKE=Pontiac

There was a 255hp 400 that came in '67 GTO's.

http://www.classracerinfo.com/Engine...8&MAKE=Pontiac

So, what about it guys ? Could you get a '73-'74 2-barrel 350 under the index, at 210hp ? I don't know how much power you can get with those little 2 barrel carbs. Would like to get some input from some of you GM 2-barrel racers.

http://www.classracerinfo.com/Engine...4&MAKE=Pontiac

[Billy Nees]

Originally Posted by oldskool

So, what about it guys ? could you get a '73-'74 2-barrel 350 under the index, at 210hp ?

For a 350 and larger combo, the only decent one would be this one. It's not without it's "issues" though. It doesn't have a whole bunch of compression and it's the only one of the GM 350s that uses a 2G carb with a 1.18 venturi (same carb as a 305). All of the others have at least the 1.25 venturi 2G.
But ya know, for some reason when ya look at the specs and the pieces that go into a Pontiac, they always seem to run better than they should.
Oh BTW, as far as I know, all 301 cranks are the same.

[oldskool]

"...as far as I know, all 301 cranks are the same."

Have never seen a 301 crank. Just going by what I've read online.

Here's what I usually read about the 301T crank.

"...a rolled fillet crankshaft..."

Don't know what that means nor if the T crank is actually different from the non-T crank, or not.

Another article describes the turbo crank this way.

"...installed a sturdier crank with pressure-treated fillets..."

[oldskool]

Originally Posted by Billy Nees

For a 350 and larger combo, the only decent one would be this one. It's not without it's "issues" though. It doesn't have a whole bunch of compression and it's the only one of the GM 350s that uses a 2G carb with a 1.18 venturi (same carb as a 305). All of the others have at least the 1.25 venturi 2G.

OK, I'd like to explore this 2-barrel thing a little more. Assuming that several of you Chevy guys have run 2-barrel combos at some point.

So, what I'd like to zero in on is the power potential, of the smaller carb with the 1.186 venturi vs the larger carb, with the 1.25 venturi.

(1) For those of you who have tried both size carbs on your sbc engine, how much of a power or ET difference did the bigger carb make ?

(2) Lookin at Class Racer Info site, I see that a '73 350 2-barrel sbc is factored at 224hp, in an F or X body, when using factory heads.

http://www.classracerinfo.com/Engine...MAKE=Chevrolet

The '73 350 Pontiac is factored at 210hp.

http://www.classracerinfo.com/Engine...3&MAKE=Pontiac

But, as Billy said, it has less compression & a smaller carb. Just makes sense that this size engine has more power potential, if it has more CR & a bigger carb. Obviously, this is assuming that the 2-barrel carb would be the limiting factor, or "choke point" of a 350 cube engine.

I assume the increased CR & larger carb would definitely give the sbc engine more power potential. I'm guessing that those 2 advantages would more than make up for the 14hp difference. But, how much more ?

I assume there are racers out there running this combo, especially in a Nova. So, for you GM guys who have done a lot of testing & racing, with 2-barrel carbs, please consider these differences & let us know if you think this Pontiac engine has the potential to at least run safely under the car's index. Don't know if the body would make a difference. But we'll assume a Ventura, which would be similar to the Nova for this question.

After all these years, I assume there have been lots of dyno & drag strip testing of different 2-barrel carbs on sbc engines. Any links to any of the results of some of this testing that might show the power potential difference between small & large 2-barrels ?