Sorry about the type-o on the part # ,that could have been ugly! eek!
I set mine at about 8* idle , these distributers come set to curve about 30* by 2500 rpm if I recall.When you get it look down inside at the plate and you will see an adjustment for the stop on the advance, they are 2 screws across from each other with a slot and stopper next to them, I run mine wide open on 92 octane with 9.5:1 modified motors . no probs NG