this may be a dumb question and yes i know 4gsk is 4000 rpm but i have yet to put my 60 lb valve springs in yet so im careful about not going over 3200 rpm but it feels like it may be defueling before then. i can def get higher rpms then with the old stock ones but much over 3k now im not sure how much higher it will fuel to.

 

i have the same issue. set at .050 my truck would only rev to 1600RPMS they now have tthe crap clicked out of them and the truck runs good revs well into the 3's in neutral but only high 2's in gear?

 

hmmm i fuel to about 3800 and can free rev to 5000 you might want to check your instal

 

yeah im gonna have to go back through it im not really sure how how shell go cus i dont wanna go higher then 3200 until the 60 lb valve springs are in. i know i can def get to at least 3200 rpm but dang it sounds like it might not be able to fuel much harder. i just didnt know how high or rpms to expect from a 4gsk

 

i did mine with no help and no tools. mine spins to 4100 in all gears with 110# springs... im guessing that you either have a shim still inside or your nut is to tight or loose....