Originally Posted by dewmanshu

this sounds like the common advice around, the only thing is I know people do it, but it seems being on a returnless system and getting 500hp out of the 42lber's is harder. Not that people aren't doing it, just moving up in injector is probably a real good idea. Soooo I'd change it up a little, once you hit 450hp-put on your mod list injectors if you plan to go after more horses. especially 500+.

Originally Posted by FlaBouy

I ran the 42# in my truck and was seeing 120% duty cycles at 403 rwhp... I added the 60# injectors and heads... Now at 500+ RWHP I am seeing 65-68% duty cycles @ 55 psi. I run the 255 lph Walbro intank.... No issues so far and I have run this for nearly a year at 11.8 afr at 5800 rpm seeing 185 kPA logged through hp tuners... Can't answer yet for 600+ rwhp... yet....