Re: which alternator do you recommend
I only do as mark w does above, ONLY 12SI, 94 ampere, and, I single wire a stock 3 wire, NOT a fancy "aftermarket 1 wire" disaster. Mine all come from wrecking yards, 10 bucks, usually NO parts needed, just clean, put back together, make the jumper for the number 2 terminal power, and, bolt it up.
I have them running on everything around here, and a LOT of non-GM vehicles.
I NEVER use the CS series alts, even the ones that are supposed to be "updated" with stronger rear end frames, they still kill the alternators from the housing beating out the rear bearing bores.