94 G STANG

Well guys i went a different route after finding out my short block was in need of 1800 bucks worth of work. I ended up decking the gt40x's valve job etc, butI dropped in acomplete stock gt40 motor non p in it to get by for now. Its got nice low end torque and pulls hard up until 5k rpms.
soon as ithits 5k it pops andI pull of not do damage anything, is it valve float??? its stock cam everything Im sure you could go past 5k rpms with stock 5.0s all day long, my timing is 14-15 degrees my maf was working good before and should stillbe good. Any ideas????

tooslow5.0

its probably valve float. if you got the gt40 motor from an explorer, they are more oriented to low end and mid range. the stock valve springs just plain suck. when my motor was stock, it fell on its face at 4500 rpms, due to float issues. just replaceing the valve springs should allow you to pull more power out of that engine.

94 G STANG

thats what I was afraid of, it makes a weird noise I dont know its not popping its grinding or something pissed me off, otherwise the engine runs so smooth and gets bad *** gas mileage unbelievable cause I always get on it. Im tired of tearing it apart.