I have and 01 GMC Sierra with a 4.8. Alot of bolt ons like K&N intake, mass airflow sensor, tornado in intake tube, JBA ceramic coated (shorty) headers, 40 series flowmaster dualed out the back, electric fans, .525 lift Comp cam, 2500 TCI stall and an LS1 Edit to make sure everything is running right. One of my friends told me is should put some 6.0 liter heads on it and was wondering what the master minds on the Gen III engine had to say. Right now my best time is a 15.5 in the quarter and want more!!!!!!!!!!!!!!

 

with those mods and a time of 15.5 I'm assuming your truck is ext cab with 3.42 gears. correct? I pull 15.6's with intake, shorty headers, flowmaster, and a hpp3

 

Don't use 6.0 heads. Their larger combustion chamber would kill your compression ratio.

If you want heads, get a set of 4.8/5.3 heads worked.

 

agreed..