[Tom Wells]

Silverback51,

I tried them on my aluminum SCJ heads. I almost ruined one bolt hole.

Two things happened that I didn't like:

1) More than one of the setscrews fell out after the car ran through several heat/cool cycles.

2) The bolt itself resembles a tap; in trying to remove one of them to go back to the Stage 8 bolts, the bolt tried to tap one of the holes oversize. It apparently didn't collapse to its original shape when I took the setscrew out. Yikes!

Having said that, they may be OK for iron heads. Definitely not recommended for aluminum.

I told them this at PRI year before last and thought they were permanently withdrawn from the market. Maybe not.

I now use the Stage 8 bolts. They are a hassle to fit, but they seem to be compatible with the aluminum heads.

Hope this helps,

Tom