[RKDinOKC]

Decided the GT cams were the best option for rebuilding broken cam and crashed head. Downside is they are hard to find.

My options were:

1.) Go back stock, replacement cam $1300
2.) GT cams, found a set for $1500
3.) Stage 2 cams and valve springs, $3500
4.) Custom grind cam and valve springs, $5000

The 5.0 liter 928S4 has 300hp. From 89 to 91 there was a 5 speed GT version that had 325hp. The 25hp difference comes from cams. When the 928GTS came out it had a 5.4 liter making 350hp. The cams in the GTS are very close to the S4 cams. Talking to some of the engine build gurus they claim the GT cams need stiffer valve springs, BUT all of the valve train components except cams are the same for the S4, GT, and GTS, including the valve springs. The ones that have done this are seeing over 40hp increase.

The Stage2 cams are not recommended by any of the 928 gurus and say if I am going to replace valve springs to go with a custom cam and a couple of those are saying they think the best cam option for the 5.4 liter is the GT cam. No one that has put in the stage2 cams has posted any dyno measured improvements.

Oh and I added up the parts recommended by THE biggest hp engine builder, he is recommending custom cams, valve springs, light weight valves, light weight lifters, etc is $11,000.