Big smallblock power..Turbo?

I recommend sticking with a Single Turbo concept...purely on the basis that it is simpler, more effecient and is easier to package.

With that, my turbo recommendations are:

Garrett GT35 with .85 A/R exhaust housing
or
Precision Turbo SC6152, with .96 A/R housing

with
40mm Wastegate with 10 psi spring
&
1990-1994 Eagle Talon Blow Off Valve

Both of my recommendations are 650-750 hp capable, and will do 40-45 lb/min with relative ease at 14-18 psi of boost.

Both would have a boost threshold of about 3000-3500 rpm.

On another note...you can use regular street gears in the range of 2.94 to 3.55 to help load the turbo up...once turbocharged the torque is tremendous and WILL PULL highway gears like it has 4.10's...so don't go jumping off and getting a 3.91 or 4.10 gear set right away.

I am a big fan of AnotherA's turbo build and wish I had the funds to do something exactly like that (except the .68 housing thing 8))

I wish you good luck.