So a follow-up question to this, do you mask off the mating surface on the block to keep that clear of paint?  I am sure paint is thinner than powder, but I don't recall seeing this done

I haven't taped one off but I do avoid spraying directly on the mating surfaces. That's with paint. I don't have a big enough oven to do a block or transmission. Chuck

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

For cleaning any residual point from the block bellhousing mating surface, I simply use some ‘Brake Kleen’ or similar product on a paper towel.  Paint comes right off.

Lorena, Texas (South of Waco)

I usually tape the surfaces


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ