Here is a fellow I've been keeping a link to, just in case my '79 should need a replacement. He sells a plug-and-play model specifically for the '79 CB750:
http://www.oregonmotorcycleparts.com/Reg_rec_units.htmlHis price is similar to what you would pay for an OEM, but his units are built to handle higher amperage, if I remember correctly. You can always call and discuss it with him. Here is a copy of his guarantee:
Many companies do not guarantee electrical parts. I don't like taking a risk buying
a part without a guarantee and I don’t think that you should have to either. I
guarantee my rectifiers and voltage regulators not to fail because I want you to be
assured that these rectifiers and voltage regulators are the best available.
In the unlikely event of a failure, mail it back and I'll replace (or repair) it, no
arguments, no hassles and most of all no BS. I build my parts from the best
components and I have full faith that they will out last the rest of the bike. See my
FAQ page for more information.http://www.oregonmotorcycleparts.com/Products.htmlCheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII