How do you trurn it and what is safe with a bone stock engine?

 

There is a jam nut on it you need a 13mm wrench for that. The scew has a slot in the end of it you turn with a flathead screw driver. It may still have the cover over it if it has never been messed with. Look in the sticky or youtube for more info. You don't want to just turn it as far as possible it won't help. Make sure you watch your pyro and tune your afc accordingly until you get a good tune where you feel good power but not a ton of smoke and EGT's through the roof.

 

Thanks! it worked great! I got it set at 2 and a quarter turns with no runaway and no smoke!

 

Good to hear

 

buy a pryro gauge, any added fuel can let the truck run the EGT's up into the unsafe range, especially when towing a trailer