what other than distributor issue would cause my timing to so far out at high RPM's?
Have you looked at exhaust restrictions like Jerry suggested? Based on the posts above, you appear have to decided that this is an ignition problem but it is not clear (to me) why.
Evan is suggesting putting a later model HEI distributor on. A bit of machine work on the shaft is needed to make it fit, but once you do that you can use off the shelf wear parts on it.
