I have a 99gmc5.3 with 70 series flowmaster and a intake. How much power increase can I expect out of the ASM's. Does the 1 3/4 primary hurt the low end torque. Can you feel the power increase throughout the RPM range. Seems that 1 5/8 longtube primary's would make more torque on a stock engine.

 

Might want to try in the truck section.