I have a chance to replace the worn out 239 Flathead V8 and 4 speed straight gear trans. With a 1956 302 Y Block with a truck 5 speed out of a F750.

This is for my 48 F6.

Anything I should be aware of?
Anything I should stay away from doing?

Thanks in advance!

 

Motor and trans mounts could be a trick. The Yblock will be set up with bellhousing mounts for the engine/trans with a single front mount for the engine. You can probably make up a plate-type mount at the front that catches the flathead engine supports, but the BH ears may foul the stock crossmember at the back end. On an F6 you should have room to fab whatever is needed.