external 390 crankshaft I.D.

[groundhog180]

Hi All,
I'm sure this has been repeated here a number of times. I thought Keith showed a picture somewhere during his resto series of how to identify a 390 or 360 crankshaft by the slots on the backside once flywheel has been removed. I picked up a spare motor today that still has the engine tag stating it as a 1971 390(we pulled from a 1971 dump truck) and the crank has one square slot on the backside. No I didn't check the stroke yet. That will be a few more days off.

Thanks for any info......Lee

[fordman]

it is a 390. a half moon means its a 360 a sqaure means its a 390

[AEP]

I have heard thats not true 100% of the time. And besides there is no such thing as a 360 crank, its actually a 352 crank. What makes it a 360 is the 352 crank in a 390 block.

[ericknight]

Pictures are in this thread.

http://www.fordification.com/forum/view ... on#p157753

Since the engine came out of a dump truck, could it be a 391 FT series?