Doug, a friend of mine experienced the same thing with his 12v system as you did. His experience was in his roadrunner and his dart. 12v batteries, 2/0 cable, etc etc. We did everything possible to the 12v system to see what its problem was, and we found nothing. He switched to 16v like I had been on him for years to do. No more issues. His dart, same story with the 12v battery. I lent him my spare 16v battery, no more issues. His dart has a 511 low compression street engine in it. Why is it that some people have such good success with 12v batteries and others do not? I wish I knew.

A Powerglide might not need a snout, but a 727 sure does. I did a bit of damage when I had an engine kickback, so I welded a snout on. On a 727 it can almost idle off the starter motor now.

thank you sir.
my plan is for a 95 amp denso alternator, and a smallish battery that i plan on mounting on a modified tray below where the factory battery was mounted and where the vacuum reserve can was on the frame rail of my charger.
the reason for this, is over time, batteries have caused corrosion and rust to form on the top of the frame rail and lower part of the inner fender, thus needing these areas to be repaired.
this car is not factory stock by any means, and i don't plan on restoring it in my lifetime. i decided to do a small battery mounted low up front, as it will be a ton less work than relocating it into the trunk.
if going this route, and using a small 16v battery and the denso alternator, what would you recommend for a battery that will see mostly street time, with very little [if at all] night driving requiring headlight use ?