Thanks Rumble. I am glad that info came out. Yes, the timing cover tells you which style cam you have. The cover with no fuel pump mounting surface (machined and tapped) gets the short cam. The regular cover with mounting area for a pump (whether it's blocked off with a plate or not) gets the longer length (regular length or retrofit cam). Now to complicate things a bit, there is a cam adapter available so you can use a short cam in a long (or standard LA) timing cover. Another thing to remember, these roller cam LA engines were change-over designs. LA went from flat tappet hydraulic cam to roller then to Magnum which all had roller cams. There may be some odd combinations out there. You know Mopar. lol I have hears of early roller 318 blocks with flat tappet cams. never say never.