The CV (Xceldyne) stuff is very nice. Thats all we ran on the cup stuff. The last big M I built, the jesel did not hit the block, however it did hit the oil galley plugs behind the cover. As far as the comp, we have used them with great luck, but it is not the quality of the jesel or CV. I think the comp with the idler would be the way to go if you are running something that has been Aline honed.