High Compression, Carb.....and Pump Gas

[PTAddict]

Chevy big blocks have a less efficient chamber design, and are thus more detonation-prone than small blocks (and the LS motors are far better yet). So normally, 11.5 static compression without electronic spark advance control is asking for major trouble.

But "normally" does not include your situation. That cam is huge, even by the standards of 500+ inch motors. More to the point, the intake valve closing point is very late, which will bleed off a lot of cylinder charge through reversion at lower, more detonation-prone RPM levels. So the compression ratio that the motor actually "sees" - often called "dynamic compression ratio" - will be much less than you would think by looking at the 11.5 static number. So I think you'll likely get away with it just fine, assuming aluminum heads, conservative spark timing, and a good cooling system.

As an aside, I think you may have issues trying to get those "self-learning" type of EFI systems to work with your cam. The large overlap cycle will dump so much oxygen into the exhaust at lower RPM that the wideband sensor will still be reading dead lean even when the actual A/F is very rich. You'll probably need to have a controller that can be manually programmed, and it is very useful to have a CO/HC exhaust analyzer available to tune idle and lower RPM mixtures, since they are still reliable indicators of A/F ratio even in the presence of excess O2.