mid 90's motor swap into my 72 k-10

[805sK5]

Im new to this forum so if it seems like im a lil bit new to this i appologize.. I currently own a 72 k-10 that i recently killed my motor in a offroad trip, its knocking, no oil pressure at idle..etc..

I just picked up a mid 90's tbi motor H.E.I with a carb swap ( set up ) on it.. the only thing im running into problem wise is what do i do about my alternator.. It plugs into the top and the new motor has the 3 wire set up.. Can someone explain or give me step by step how to swap these? or can i just use my old alternator with a different pulley.Will that old alternator be powerful enough for the h.e.i distributor?. the new motor has the serpentine belt set up on it.. ANy and ALL help is seriously appreciated!~