Ford Repair: Mustang engine, bolt holes, head bolts

Question
I have a 65 mustang. I have been trying to figure out what is the size of the motor. I have decoded it and to the best of my knowledge it is a 1978 motor that came out of a Lincoln the code is-D8VE on the block. It has heads on it that I believe are 351 heads and the code on the bottom reads-D00E,so they should be 1970 heads off a Fairlane. I don't think it is a 351 and it can't be a 289 if I decoded it right. So can  you put 351 heads on a 302 or could it be a 351 motor? I just wanted you to verify this information that I have and if you can tell me a better way to find out what size it is please do so. Thanks.

Answer
Klay-

  Well you've done about as good a job as I could decoding the numbers.  351 heads on a 302 are a pretty common modification for people not wanting to pay the money for aftermarket heads, so it's quite possible that you've got a 302.  Then again, it's equally possible you've got a 351.  About the only way I can give you to tell them apart are the size of the head bolt holes.  302s use 7/16" head bolts while 351s use 1/2" bolts.  To put 351 heads onto a 302 you need head bolt bushings (not hard to come by, but you can usually tell when they've been used).  I suppose it's possible to drill the block to accept the bigger head bolts, but that'd be pretty uncommon.  Hope this helps.

Steve