
Originally Posted by
LamboDoNoMo
i got port and polished stock heads, and switched to the TBSS 90mm intake and shaved over a half second on my 1/4 mile times, on motor.

maybe that'll help with your decision.
For clarification: The ET change was with both listed mods or just the intake?
99 C5 cam/boltons 400rwhp
10 Sierra CC 6.2
03 Suburban 5.3