So I have a 3 valve aluminum block in my car, I've been going through a whole host of belt alignment issues since I rebuilt my crank pulley... well come to find out (via another stock crank pulley) the relationship between the front cover surface to the heads etc is different with this block. I haven't been able to tweak my pulley back far enough to tell how much, but it looks to be at least .125" forward of stock. Anyone else run into this? I'm going to have to be creative to solve this problem for my application....