I know this is a really old thread but just reaching out to ask;
I am installing a 383 b block in a 50 Plymouth business coupe and have a couple questions about your motor mounts.
They appear to be bolted in vs welded, did you drill the holes in the frame with a hand drill?
Did you tap threads for the bolts or did you secure them with nuts? If so, did you have to drill holes on the opposite side of the frame to get the nuts to the bolts?
If anyone else knows the answers to my questions, please feel free to respond.
Thanks!