[GTOKIDRH]

Originally Posted by Sirrotica

Rough figure is 3% of power increase, per 1 point of compression, there are better ways to get that 3% IMO. For sake of discussion, 400 CU IN at 300 HP, raise it i full point of compression and gain 9 HP. You may not be able to run pump gas at that 1 point of compression increase, so then you'll be either changing cams to bleed off low RPM compression, or blending race gas.

I could gain 9 HP with a sharp tune up, bringing the timing in sooner than stock, and richening up the carb and still run pump gas.

I would guess that there is something fundamentally wrong with the OPs engine for it to be such a slug, I worked in a Pontiac dealership in 1970, those cars weren't as slow as he's describing his to be.

I have seen some Pontiacs that someone changed the timing gears, and chain, that were 1 tooth retarded, and run like he's describing. They'll run smooth, but have no low end power whatsoever. Reset the timing gears, and it runs like a different car.

Cutting dishes in pistons is pretty expensive when you can go with a larger CC combustion chamber, and run the stock short block with flat top pistons, but I tend to be practical, and try to save money, especially when it's my money.

I've used Pontiacs from 326 to 455 in daily drivers, used them in Jeep Wagoneers and Jeep tow trucks, plus raced them on oval tracks for years, they aren't slow unless there is something wrong with the internal engine components, or the tune up is way way off. Almost all of my vehicles that were driven on the road would run on pump gas, and were under 9.5 compression ratio. A few of my GTOs were factory rated at 10.5 to 1, and the race car was 12 to 1. I got a lot of work done with relatively low compression Pontiac engines over the last 50 years. All had iron heads.

Thanks for the intel! Again, the stock engine in my wagon has the low compression 8.6:1 pistons as well as the large chambered heads. My thought is I already own the 670 small chambered heads which will only push me into rhe mid 9s compression wise which is still pump gas friendly and I will gain 3% more power than why not? It's free. I won't change the heads until I do the cam swap. I'll be in there anyway. I admit that i know just enough about engines to get myself in to trouble. Still much to learn. Thoughts?

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