Just wanted to add to this post by saying 70 or 80 passes with some street driving and dyno time on my car and timing chain looked good when i took it appart. I run 325# 0n the seat but i also made dam sure the cam gears line up perfect using a straight edge accross the 2 gears. The stack up of tolorance of the crank snout,gears,front of the block ect effect how the gears line up and if you dont check it your asking for trouble IMHO. Ive heard the guys that had chains fail didnt check this and found the gears were not lined up. The first stage motor i build for a guy was hard on chains until i lined the gears up perfect and after 100 passes the chain looked perfect. This is just what ive found that works for me so i thought id share...