I used an older block and crank (orange paint on block) in my rebuild with a newer damper and things are not timing up. I investigated a little further and may have a solution. Most of the Chevys we have have the timing mark back 10 degrees behind the keyway. I believe my my crank used the older 2 degree behind the keyway setup and as a result won't work with the timing marks. I need to an accurate way to make a mark 8 degrees over. I got creative and remembered that pi (3.14) times the diameter of the damper (8") will give me my circumfrence. I then divide that by 360, multiplied by 8 and got .558". Am I on the right track here or not. I found TDC kinda by moving the motor by hand using an old dip stick in the hole for #1. The new mark is about double of .558", so a little over 1". I was timing it with the gun and things seemed where they should be now with that newer mark. Did I do something wrong here, can anyone tell me that a little over 1" is correct. .558" only gets me halfway there.