Originally Posted by PERRINJeff
The OEM sleeves are about 2/3 the thickness of the STI sleeves. This is just the Iron part of the sleeve. The aluminum part of the sleeve is also smaller than the STI, but HP per cylinder is still lower than the STI, so it should hold up. Key word there..... SHOULD.
I am going to have to disagree on the thickness, from my eyeball and pictures I took, all of which are in my thread, the OEM sleeve from the H6 and the STi sleeve looked identical in thickness at the access hole. I don't see any reason why the taper would be much different internally but who knows as we never cut one apart, unless you have since then. THe exact numbers are somewhere in my thread but overall aluminum sleeve thickness at the top is only like a .7mm difference with much less hp per cylinder(I know you know this cause it was a point of discussion we had, haha). So yea, I agree it should hold up, just wanted to add that observation because originally we assumed and i was told it was a lot less thick, but no one had checked, so I checked and saw no difference. I could have been wrong though, but my eye is accurate enough to pick up on a 1/3 difference in thickness.
that is all.
continue with technical discussion.