So my alternator went out this weekend a the lake had to get towed into the docks bummer,  but it was the end of the day anyway. So my local rebuild shop is closed (holiday weekend) so I pulled the alternator off and did some investagation on it. Turns out it looks like a standard ACDELCO Alt. under the Rear screen cover. The only difference is the rear cover added over the original rear case cover and the internal screen on the front cover under the pulley. So I took it to Autozone to get it tested as is and they couldn't perform the test because it goes to a boat (test plug didn't fit through rear marine cover). I took it home and took it a part, took the covers off and removed the screens reassembled it and took it back to another Autozone. I told the it went to a 1985 chevy pickup with 454. they put in on there tester and it failed, as I suspected. So I bought a new one with life time warranty, compaired them they are the same. So I opened the new one up installed the screens and covers and I got a new Marine Alt. with a life time warranty for 69.99. Anything wrong with that? Lake tomorrow 

Probably be OK, our Marine "one wires" are self exciting (require only one lead) , if you use an automotive and use the 12v switchable lead you need to be sure it has a diode in line (your  harness may have already this) or we've seen the Automotive units keep the motor running after the key is shut off Tom