Originally Posted by nickmckinney

Not many 2V with combos that would last any significant amount of time. I keep a stock head on display at the shop from a motor like this, you can dance the exhaust valves around the exhaust guides are so worn out, the clearance went from 004 stock to 030 give or take in under 30,000 miles.

You can do 400RWHP all day long, but getting to the 500RWHP point pretty much the entire motor needs to be tweeked some if you want it to last.

Originally Posted by EI-03-GT

when you say rework the heads are you referring to the stock PI heads or all aftermarket heads?

Originally Posted by tbirdscwd

Hmm, didn't know that. Is that a typical result you see from the exhaust valve at that power level? Can't say that I've heard of people having that issue.

Originally Posted by nickmckinney

2V wear out the guides, 4V drop the seats completely (over 20lbs of boost).

You see it over and over enough you add 2+2 and get 4 sometimes.

Originally Posted by nickmckinney

There is only one aftermarket head for this motor and it comes already set up if you get the higher spring seat version.

Originally Posted by EI-03-GT

no there are a couple of them. trickflow and patriot are two makers of cylinder heads that i know about. i know that trickflow is the only head that just isnt a ported version of the PI heads though