Oldsshagginwagon

I know I’ve asked several questions in here but does anyone know of a good place in ky to take an olds motor to find out what exactly I have (i.e. bank angle, piston size, heads, basic info on the motor.). Thanks in advance.

v8al

Post pictures of the block casting number behind the water pump. That will tell most of the story.



For the heads, get the letter code that is found on the front of the drivers side cylinder head.

v8al

If it's a 1965 425 like your other posts it will be block casting # 386525 which has .842 lifters and a 45 degree lifter bank angle.
Stock bore will be 4.125 inches.

The heads will be letter code "A".

The two main things to watch out on this year engine are:

1. The 45 degree lifter bank angle. This will require a 45 degree cam. Most Oldsmobile cams are for 39 degree lifter bank angle.
2. The heads use a one year only 3/8 stud setup for the rockers.

Pretty much everything else will be the same as every other big block Oldsmobile engine. (except flywheel, crank, balancer, pistons and rods)