Mancini Racing Big Block Alternator Mounting Kit 1967-68 vs 1969-72

I'm adding A/C to my 1985 D150 with a 383. I'm using Mancini's passenger side water pump housing MRE86950 to match the rad that is in the truck. I have a non-A/C alternator bracket setup on the 383 now with a square back alternator. I don't have any A/C setup brackets. I'm looking at Mancini's alternator bracket kits the 1967-68 MREHF6040-KIT and the 1969-72 kit MREHF1746B-KIT. Is the earlier kit for the round back alternator and the later one for the square back, is that the difference in these kits? I emailed Mancini 10 days ago and haven't heard back. Anyone have experience with either of these kits? In my application is it going to matter what one since nothing about this is stock. Thanks.