Post by 1partshelp@gmail.com on Aug 26, 2019 15:49:51 GMT -5
I just tore down my 65 400. I am kind of curious about the pistons. They are flat top and have two v notches together on the outside. Inside the number is 389299 and it says GM. I can not find it in the parts book. Because it says GM I am sure they are original. The diameter is 3.9565 the wrist pin diameter is 0.9865. There are two F's one on both sides of the wrist pin. A1 with a circle around it above the GM. If anyone can tell me about this piston I would greatly appreciate it. Thank You Jim Hald
