Pinion shaft differences early to mid ironhead

[ricochet]

I see from looking around there are differences between the 57-76 and 77-85 pinion shafts and a somewhat corresponding change for the crank assembly as a whole for the same timeframe.  What are the changes and can a later crank assembly and pinion set-up be used in the 76 and under cases? If so what needs to be addressed?

Thanks folks,

ricochet

[ricochet]

So the baseline question is can a 77-85 crank assembly be dropped into a set of 73 cases and what's involved?  Any machining?

ricochet

[wreck74]

I would'nt think so, differant sprocket shaft, differant pinion shaft, change them two and it should work.

[ricochet]

The pinion shaft looks quite a bit longer and is threaded.  Is the cam cover on 77 and later wider or have deeper recess to accomodate this?  I see all the differences in bearing arrangement, ID, OD, etc.  Is this 77 and later cranc what's referred to as the "commonized crank" which has different tapers I think?

ricochet