313 poly compared to 318

[Kiwi]

Hi guys. Aside from the bore is there any other difference between a 313 and 318 poly engine? From what I can find info wise in them both motors have the same stroke and the 318 seems to be about 30thou bigger in the bore. Are the cylinder walls, water jackets etc all the same or do they differ? I have found a 313 in parts over here and thought it could be the makings of a stroker engine or at the least a nice rebuilt engine if i can get the same bore out of it as I could from a 318.

[RICKYMOPAR]

The blocks are the same casting number as well as the 326. I would feel fine about bore and stroke modifications. If you go to a four inch stroke be advised to clearance the block at the lower cylinder bore to clear the rods and bolts. This is not a complicated process, carefully using a die grinder and a sharp cutting burr, like a file. stones work but leave behind debris harder to remove. Cam shaft, and pan rail clearance will not be an issue like on the Chevy small blocks. I relieve about .10 of an inch allowance. If you do this on a newly bored block make sure to remove any burring in the bore, and a good cleaning of the entire block.

[Kiwi]

Awesome info Ricky. Thank you.