I just put one in my truck this evening. I don't know if I did something wrong in this truck or my old truck. My old truck had the same mods as this one, but this truck is killing my boost gauge with this spring. The old truck would run around 33 to 35 psi at the max, this truck is probably eating about 40-45 (it's only a 35 psi gauge, guess I need a new one). The gauge wraps back around a quivers really hard on the rest peg. Any input on this? Only complaint is when I really hammer it, the pyro gets up there pretty good. About 1600*, but that's only under extreme beating.

Nobody else has had this?

I get about 35 psi max...

That's about what my old truck would get, and I thought that was good. Like I said I have this truck set up exactly the same, pump settings are all the same, same injectors and turbo. I have a 60psi gauge coming later on today, I guess I'll see what it's actually getting. Also, WOT smoke is much greater than the other truck was. I thought maybe this is because the old truck was equipped with 4.10 gears and this one has 3.54's.

the spring should not have affected your boost at all. it only changes the amount of RPMs. you may have moved the power screw when you were in there. Also no two trucks are the alike. every injection pump will react differently.

^ What he said. ^

Well, whatever happened, it's holding 45psi. But once it gets over 42-43psi the gauge quivers pretty good until it hits about 48psi and it will settle back down to about 42-43psi again. If in fact I did bump the power screw, I didn' think I did, should I turn it down a bit? You guys think this is a bad thing?

i think many guys try to keep it under 40 on the stock head gasket.anything over that is not worth taking the chance. i am sure you are not doing much good with anything over 40 psi becauseits just hot air.

Ok, I guess at 42psi it's not really a big deal then. Thanks for the advice.