F and 2F Cranks the Same?

Skreddy

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Looking at part numbers, looks like cranks for all the engines are the same from 68-ish on up. Can anyone confirm or deny this? They look the same. (Threaded on nut for balancer, not press on balancer).
Reason is, the crank out of my red 77 (2F) spun a bearing and tatered the rod on number 5. Got it hot enough the throws on 5 are black from heat discoloration. Machinist says it can be turned and clean up but with the heat coloring and it’s already .5mm under, he said if I had a different crank he’d go that route. I have 2 cranks from 1970-72 F engines that have never been turned and the bearings look good. If these are in fact identical, I plan on having the better of the 2 cleaned up and use that rebuilding the 77 2F. I also have a 2F from a 75 I planned on pulling a hood rod and piston from and possibly just use that crank, if it matters.
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65swb45

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Yes. There is an exception for the very late 2F that uses a different thrust bearing on #3 main.
 
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Mark, that’s the kind of tech that comes from a lifetime of wrenching. I, along with many others, very much appreciate it. Thank you sir for sharing.
 

Skreddy

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Yes. There is an exception for the very late 2F that uses a different thrust bearing on #3 main.
Thank you very much!
 

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