Join Date: May 2001
Location: Chattanooga, TN, USA
That's alot of questions......Most can be answered by "what do you want"
If the block is the original L48, and you are doing a restoration, I'd use all the original heads, intake, carb, manifolds, etc. If you are doing a street rod, especially if the block is not original, I'd put whatever performance upgrades you want.
As for the compression, most will say you risk detonation with pump gas for compressions above about 9.5:1. Although you can retard timing to reduce/prevent it.
If I were rebuilding the motor, I'd choose pistons that would allow use of pump gas. If I were not rebuilding, I'd use octane boost or blend a little racing fuel to kick the octane a little. I talked to a guy with a 67 chevelle 396, with 11:1 compression. He kept a coule of those short, square 2 gallon plastic gas cans with racing fuel, in his trunk. He added one can with each fillup of 93. That was enough to raise his octane.
He made an angle iron frame to keep the cans from sliding around in the trunk.