73 Scamp with 318 "La"block.........made into 360?

[ScampMadness]

Hi everyone I have a 73 Plymouth Scamp with a 318 2bbl.......I have been told this is the "La" block which during the same year was also the basis for the 340 and 360 motors.....is this correct? and if so what would I need to make my 318 and turn it into a 360? Right now the block is down at the machine shop getting inspected. any help would be greatly appreciated. TY so much

[Stoga]

Yes, the 73 318 is a LA motor, but there are too many differences to be able to drop a 360 crank in your block. One, the 360 crank has larger crank journals, 2.81 for the 360 compared to 2.50 of the 318 or 340. A 340 has a larger bore then a 318, 4.04 compared to 3.91 inch on a 318. 318's switched to a cast crank in 68, except for trucks which used the 318-3 engine which has a forged crank. I would suggest just regrinding or replacing your original, and putting it back together. Or replacing it with a 340 or 360 if you want more cubic inches. Even swapping in a forged crank from a truck will require swapping harmonic dampeners, flywheel or flexplate, crank pulleys and possibly several other things. 318 is a good motor, but if you want something larger and don't want to pay for custom machine work, get another engine.