If I put 12lb with my KB kit on a stock 4.8L should I change any thing, like fuel pump or spring and valves?

 

fuel pump, injectors a gooood tune, just to start i would think. Some of the more exp. members could tell you what all you would have to do

 

Might want to start thinking about a new motor now............

 

what he said your motor should be fine i would do some data logging to see and make sure everything is ok. but forsure 12lbs is max unless you do some internal work

 

Build a intercooler or add meth. You need to watch your injector duty cycle as well, not sure how much boost it takes to max them on a 4.8 If you do not do some type of cooling your IAT's will kill your timing. As others have said make sure your tune is spot on, what injectors do you have? I would do a 255lph fuel pump if you have not already.

 

You will max out your factory injectors and fuel pump with a 4.8 at around 8psi. Ask me how I know.

 

add parachute.


J/K, what they all said, +1

 

Ask TurboGibbs. He has some experience in this area. Actually I would say the biggest concern would be adequate fueling. I was hitting 86% duty cycle on my 4.8 with 10 psi boost and marine 42 lb. injectors. For 12 psi, I would recommend 60 lb. injectors and a fuel supply upgrade to ensure that the necessary volume and pressure can be maintained. Might also want to consider water/methanol injection just to cool things down. Some people have used the methanol injection to patch over shortcomings in the fuel system, but IMAO that is courting disaster. Otherwise, as long as you avoid detonation, you should be fine. For some strange reason the 4.8 seems to be able to take more boost than the 6.0 without breaking parts.

 

You will need a built tranny in short order too. The stock one will not last very long. I hope you have a fat wallet in your pocket.

 

Well I do have the KB kit that came with 42lb injectors and intercooler, yeah I got some money just hoping alot of the stock parts hold up. I was thinking on doing spring and valve work. But thanks for the advice guys