I've Herd About Bypassing The Omc Shift Assist But Don't Know How. Will This Work With An Hei Distributor??

Petronix distributers come with a diagram to do just such a thing. I will see if I can find that old sheet with the diagram.

It will be a bear to shift however...

The diagram is buried somewhere on the Pertronics website.
Why do you want to bypass the shift assist?

You can't bypass it and still have it shift properly. I converted my point distributor to electronic which required a bypass circuit for that. It protected the electronics from the shift interupter. It didn't bypass the interupter. Could this be what you're after?

You can hook it up like a Mercruiser. The wires out of the switch go to a plug. Pull them out connect one to ground and the other to the - side of the coil. When you shift it will kill the engine for a microsecond to allow it to come out of gear. This works good, I've done it several times.