Thread: Compression Ratio

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First off, you don't want horsepower, you want torque.
Secondly, you don't need lumpy, lumpy is for posers who don't know any better. Lumpy is the sound of a motor being inefficient because the intake valve is opening too soon for the rpm where it's lumpy and the burned exhaust charge that is supposed to be pushed out the exhaust valve is instead being pushed up the inlet tract, disrupting the signal to the carb and screwing up manifold vacuum. Lumpy is for the guy at the drag strip who has a hot motor that makes high-rpm horsepower, but won't pull the hat off your head at low r's. Lumpy is for guys who have to make other arrangements to operate their power brakes because their cam won't make sufficient manifold vacuum to operate the brakes and other vacuum-operated accessories. Screw lumpy.
Thirdly, to make decent torque at 2K rpm's, you need a stock cam, but you won't make 400 ft/lbs of torque with a stock cam.

Now that I have that off my chest, if you want a high-torque 350 (it doesn't even take a 383 to do it), go to this Air Flow Research site, http://www.airflowresearch.com/ ,click dyno tests at the top of the page, then click Chevy dyno tests. The first test shows a 350 with 180cc heads that makes over 400 ft/lbs of torque from 2,700 rpm's through 5,000 rpm's.
Buy their 74 cc heads and with your flat-tops (7 cc's of valve relief) and a 9 cc gasket (0.039" compressed) and zero deck, you'll be at 9.07:1 and can just plug in the components they used to make power.

One last thought, you don't adjust compression ratio with the head gasket. You do it with the piston and the chamber volume, then you use the correct thickness gasket to set your squish to between 0.035" and 0.040".