I want to change my gmc truck to a new style alternator from a generator how do i wire it in?

Wow, how old a vehicle is this? The generators have been gone from most GM products since the early 1960s. I converted my 1961 Chevrolet from the old generator to an alternator, but this was in the days before the regualtors were built-in. The biggest three problems for me then were: Getting a top bracket for the alternator, since the alternator was different from the generator it replaced Making sure the external regulator was integrated into the ignition system for the initial voltage to operate properly (and making sure the dash ligh worked) and

one minor operational problem, the alternator would not charge properly at first crankup each start. I had to get the engine RPM up above an idle to get the regulator to start working, and getting the alternator on line to charge. Quite simple, now, actually, since the newer alternators have internal voltage regulators. The mechanical part of mounting the new alternator might be a bit of a problem, but I'd submit a friendly GMC parts guy might be able to look at some old parts catalogs and determine the different mounts GMC used in the first few years of alternators in that engine series.