I found a good deal on a recently rebuilt engine that I'd like to put into my '57. Unfortunately the PO painted it chevy orange. I'd like to re-paint it an appropriate 6 cyl color before installing it. It only had a few miles after the rebuild so it's not dirty at all. I'd like to just wash it good, go over it with a scotch brite pad, and re-paint with the correct color for a '57 truck which I believe to be grey. Will this work okay? I don't want to have the new paint peeling off and leaving me with an orange / gray dalmatian looking thing under the hood. Any advice will be appreciated.

'64 swb stepside (gone)
'57 1 ton
'53 phone truck
'59 swb
'46 1 1/2 ton
'68 swb gmc