A-302 Or R-302
 

Dose any body know the difference

A4?
 

When you say 'A-302' are you referring to the A4 block? If so, it's my understanding that Ford improved this block and renamed it the R302. I used to remember some of the differences b/t the two, but can't for the life of me seem to recall them now. However, I think a similar thread came up a while back (maybe ~year ago) so you may want to do a quick search and see what you came up with.

Hope this helps.
E

An R302 has 4 bolt mains ( middle 3 anyway) and they are 1/2" bolts. A4 is only 7/16" I think. Not sure about the A4 but R302 also has 1/2" head studs. They no longer make the A4 you can only buy the R302 now.

Off the top of my head (correct me if I'm wrong please), I'm going to say that the A-302 is an Aluminum block... look around the net and do some searches and you'll be good to go. ;)