I know we are all about Pontiacs but for some insight to what 285 cfm heads(Brodix 11x), 406 cubes, 6000 rpm redline, intercooled turbos are capable of, check out this SBC 406 from Nelson's shop. On 91 octane and only 7 lbs boost 769 hp, at 14.5 psi over 1000 hp on 91 octane. Adding 110 octane race gas and upping the boost to 18.3 1165 hp. Changing injectors and upping the boost to 28 psi netted 1502 hp at 5600 rpm. BTW Brodix 11x heads advertised flow is not terribly different than out of box E-heads for a Pontiac.
Here is the link.
http://www.hotrod.com/projectbuild/h...bocharger.html