my bosses 87 gmc has a garret AR 60/AR 96 turbo, boost starts dropping off at around 4000 rpm with the waste gate fully shut..what would be a good size turbo for this? its a 87 gmc sbc 350 with a mild cam and edelbrock fuel injection..

 

How much boost are you looking to run? HP level?

 

What size turbo is that? It's sounds pretty small, but how small can it be with a .96 A/R exhaust housing?

 

got some things fixed on it ..it was makin 317 rwhp and 482 rwtq with boost peaking at 13 and start dropping off at 4000..but its fixed now..did have a 4 pound spring with a regulator and the spring was just too small..put in an 11 pound spring with out the regulator..holds at 11 pounds now