Hi there a newbie here.
Owned 3 Olds for about 6 years now. Gonna rebuild a 425 and I have two to choose from. I have a 425 out of a 1967 toro that (I think) is the 39 degree (with the drill spot) and I my buddies son has a 1967 425 out of a Delta 88 without the drill spot (which would be the 45 degree angle I believe).

So is there advantage to either? I don't care which way I go. Just looking for info on the best performance and anything else so I can decide and get my camshaft ordered.

Thanks!

 

Depends on if your going with a roller cam or flat tappet.

 

Going Flat tappet

 

Absolutely no doubt the Toro motor is the way to go.

That is the best you can get in my opinion.

Notwithstanding all the cam ramp factors and the slightly larger lifter, the Toro engines were always made with the very best parts, assembled meticulously. You may find that you need to do little or nothing to enjoy it for another 40 yrs. If it does not have obvious large problems, I would not rebuild it. It would take $5k to do better than the factory did.