I am converting a military 302 GMC to civilian use. I lost some notes and I need to know if the military crankshaft is fine to use or, does it require replacement from a civilian 270 or civilian 302?

If my memory is right, I believe that the weight of the 270 and civilian crankshafts are lighter and that's about the only reason to switch them out.

Can someone give me some advice about this? I have a 270 crank and flywheel but it will require turning, balancing and new bearings while the military crank and bearings were never used. This 302 I have came off the shelf as a rebuilt and never used.

Thanks.

Hi Hunterdude . . . I am no expert on Jummies but I am pragmatist.

If your military crank is unused NOS with ready to polish bearing surfaces and it magnaflux checks as crack free - why not just give it to a crank shop and ask them to put it on a diet and then polish and balance it?

Have you weighed the two pieces you have in hand? How much lighter does the military piece need to be?

regards,
stock49

If the 302 is rebuilt then it was probably turned. See if your 270 will clean up at the same size and use it with the bearings you have.