Whats the difference between the 302 and 351 blocks?
Deck height, main and rod bearing sizes, overall strength.
A 351W for example has bigger mains and is much stouter than a normal production 302 block. Almost everything else external, with the exception of distributor, intake maniforld, and damper will bolt up. You do have to watch the external balance! Cams are the same (watch firing order).
For a cheap hotrod, the 351W is a great choice. The head bolts are bigger, the bottom end stronger, the rods are longer.
I am building a 302 and a guy has a 351 5 speed car for cheap! I am lookin to bolt a 5 speed behind my 302! Will the 351 bolt pattern be the same as the 302 and is there any other mods I may have to do to make this work?
The bellhousing and transmission and clutch will work. Be sure you watch the clutch linkage used to be sure you have what you need there! Watch that external balance to be sure the 351 (whatever type it is) has the same external balance as the 302 you have. If you mix and mismatch the external balance wrong you will have a shaker hood, and not in a good way.
I generally used my 302 parts from Fox model mustangs on 351W blocks, and the reverse would be true.
What 351 is it?? What 302 do you have??