According to Rick's the proper rectifier/regulator they have for the 77 has 7 wires...there are three going to the rectifier and 4 at the regulator.
Everything I do on this is a learning experience, but then I'm no bike mechanic. The only reason I'm replacing the voltage regulator is to be sure I've gotten rid of all my gremlins. I am also replacing my coils and plug wires. My bike has had issues with a couple of cylinders seemingly running rich. I had the carbs cleaned once and it ran like brand new for about 4 hours, then back to the same old problem. I couldn't get anybody to adjust my valves and after 10,000 miles, they probably needed to be adjusted; they hadn't been adjusted since the initial warranty adjustment at 500 miles I think it was. So, I did it myself, yeah I messed up but, I know how to do it now and pretty quickly.
The shop I took it to decided to tear my bike down and see if what I did was correct and they found that what I had done was good. That should be on them. But, they hadn't been paying their rent and got the boot. The owner should have let me know, it's not like he didn't know he was way behind on his rent when he took my bike in. At any rate I got most of my stuff back and now have to clean it all up, re-install the carbs after buying, top cover gaskets, boot clamps, battery holder bolts, new fuel lines and filters and then a new battery. His mechanic made off with my Klymers manual, that I let them use too. Once I get it all back together I'll still need to get the carbs synced and properly jetted, that's why I took it to the shop in the first place. IN the mean time I've got another sweet ride, a 2006 Honda CBR1000-RR...when I'm done with the KZ one of the two bikes will get sold.