Iron Head 1000 Max Bore

[MrMark]

Just how big can you go and maintain longevity.....  .070 .080 ? 

[JK]

Late '73 and later cylinders can go to +.070" safely.  '72-E73 cylinders, +.020".  JK

[Hillside Motorcycle]

If more power is what your shooting for, you can install an S&S 4 5/8" stroker flywheel/piston assembly. 74 CI.
Set up correctly, you can show a lot of folks your tailight.

[help-u2]

many years ago i did the 77 inch storke.  (1974 cylinders) then went 60 over cause of the welding up oil return holes and wear... its been that way many years and miles...
granted, i dont run it as hard as in old days.  still reliable as can be...
fun ride.  i take it out a couple times a month.  old broken leg dosent like to kick start it..
good power to say the least...