ok ive found a block out in a farmers garage and i dont know if its a 360 or390 i do know its an fe by the spark plug pattern and valve cover bolts but how do i tell the difference. between a 360 and a 390?

 

the blocks are the same, the difference is in the crankshaft. 360 has a 3.5 stroke and 390 has a 3.78. bore is the same

 

What does the crankshaft flange look like where the flywheel bolts to it? If memory serves me correctly a 352 / 360 (3.50 stroke) crank will have a half moon shape at the edge of the flange and a 390 will have a square cut notch in the flange. You can also take off the oil pan and figure it out that way.

 

thanks ill take a look at that tonight and let ya know my findings thank allot!!!!