Forged crank and Pistons are the strongest right?
how many cc's are stock 72 j heads?
What is the max compresion ratio for pump gas 91/92?
solid street strip motor?
Forged crank, rods and pistons are the way to go. The stock J heads have open combustion chambers, and they can be ported to flow better, but because of the open combustion chamber you won't be able to build quench into the engine build, thus the engine will be fussy on the quality of pump gas for street cruising. Proper quench also lets you run higher compression and avoid the onset of detonation. More compression is more torque and Hpower. Quench is the distance from top of piston to bottom of flat portions of cylinder head combustion chamber. A measurement of 0.040 to 0.045 inch is considered good.
Max compression ratio will depend on your elevation above sea level, whether you run cast iron or aluminum cylinder heads, and maybe how much street use the car will see. For aluminum you should run about 1 point higher compression than for cast iron because the AL disipates heat much quicker than the iron.
I am running 10.8:1 compression with aluminum heads and 0.045 inch quench clearance; the engine runs well on premium pump gas with no detonation issues at my elevation of 5000 feet.
