So… perhaps the upgrade to the CV might be the way to go…. There is one available here part No: 27650-94 (Described as MT350?) Will this fit the 86 Heritage?

 

Pretty much a CV is a CV is a CV. I'd find a decent take off and freshen it up. You will need a new manifold and gaskets, that will probably solve the real problem and the bike will run gangbusters.
You will need new throttle cables too.

PS. I felt the same way as you with my 86 but, I also remember how bad those bikes ran, always had a flat spot. Threw on an S&S E that was hanging around and couldn't be happier.

 

There is always a balance to strike between originality and just plain bad. Had the same debate on the restoration of early Indians. I came to the conclusion that if you are going to ride the bikes then what ever makes it a good reliable ride then it's OK. The original designer/ manufacturer would have wanted it that way other wise we would still be on horses!
I guess that's for another section of the forum.

 

First mod I did to my bike was to take off the CV and install a Super E.
I have been much happier with it than I ever was with the CV!!!!