The drawing above was originally produced for Ton Pels, MD of the Harley parts specialist Zodiac International BV in Holland, and was part of a major set of drawings I produced for them, depicting all the big-twin motors H-D ever produced (Up to the 88 that is).

These images below are crops from larger pictures. Just click on any of them to enlarge it.
None of the images are any bigger than 90K.