We got a 2-piece comp on a bbc in a fed that has given no leaks or problems.BUT,it only has about 250-300 passes on it right now.Can't say for sure,but seems to be just fine. The extra idler scares me personally. That's a pretty small bearing in that puppy.I haven't done the math,but I would say that around 7500 rpm's ,I'm sure that little bugger is gettin' on with it. Seems like alot to ask out of such a small sealed bearing.Our block has been align-honed and we got a drive without the idler.It's fine SO FAR. I would just about chose one on price or parts availability since it sounds like noone has really had bad luck out of any of them.Just my two cents.