Alright I'm getting conflicting info. I have read that early 80" jugs are actually just 74" jugs punched out to +.060 but also read that 74" jugs punched out that far are on their death bed. I have read that the 80"ers can only be punched to +.040 then they are paper thin. If the case is that the early 80"ers were just 74"'s punched then that would mean they could be punched to +.100 correct ? I am thinking about building my 74" to an 80" and wanna know if I can re use my cylinders. They are at +.060 right now. What is the skirt thickness on a set of early 80" jugs ? And is there any help for the insanity I have bestowed on myself ?

 

in stock form OEM 74 jugs 3 7/16 work just fine at ,060 and that is also stock bore size for 80 inch 3 1/2 inch bore

but .030 is the most i use on 80 inch - they the 74 and 80 inch jugs are made different in that 80 inch are as thick as 74 jugs but the fins are closer to the bores on the 74 so over boring any more will crack them while riding it

 

If wanted to turn a 74"er into an 80"er, would I be better off getting new 80" shovel jugs and will they fit a 74" case?

 

Gonna need flywheels too.

 

In January 1978 the cylinder castings were changed so the 74 and 80 could use the same casting. It had a thicker base then the earlier castings and required longer studs. I had 2 1979 low riders. One an 80 the other a 74. The only way to tell them apart was the VIN.