Just a idea for you to keep in mind. The alternators on the 1st gens are some what pricy even rebuilds and most of those blow. What I did was used an early style gm alternator with the internal style regulator. All I had to do is slighly grind down one of the mounting hole ears on the alternator and swap out the old pulley and she works great. If you were to look at it, the gm alternator looks as though it came from the factory that way. Oh yeah the best part is gm alternators are real cheap approx $35.

 

I'm pretty sure you can pull a alternator off a 24Valve and put it on a 1st gen. Or at least use its guts. The PO of my 1st gen spent $400 on a mean green alt. I to it to me buddys shop and he said it was just of a newer truck! And also Early 1st gens dont have a computer! :-) on the later 1st gns the computer had the voltage regulator built in it. So if the voltage regulator was bad you had to repluace the computer OR wire in a external one. The " heater relays" are just solenoids. Get at CONTENOIUS DUTY solenoid!. Not a Starter solenoid! One from a winch will work. Starter solenoids are made to start ONLY the coils will burn up and contacts will burn.