Rice, that is basically what I've done. The all knowing, "don't ever argue with me" Dan claims the way around this is to "use a smaller alternator." I say, there's more than one way to skin a cat.
I also say that these bulkhead connectors WERE NEVER big enough. Way, way, WAY back in the '70's I had the optional 60/65? amp alternator on my 70 sixpack car. I had a MINOR amount of amateur radio FM gear in the trunk. This gear, by todays standards, drew very little, certainly less than a modern trunk mount "big" stereo amp. It wasn't long before I was reworking the ammeter circuit.
Back then, I didn't realize that a sixpack car would one day be a millionare's dream, so I just drilled out the bulkhead (yeah, imagine that, and before Al Gore invented the internet) and ran two large ga. wires through there
I also found 3 or 4 other peoples cars in the same boat. Some of these were C barges, with A/C and other accessories, but once "we" learned of the problem, when a guy had charging issues, you learn what to look for.
Another note is that I've found at least 3 vehicles with bad alternator connections. One was a melted ammeter, the others were bad connections/ connectors, all caused the same end result
And, I"ve found 4 cars over the years that had a FAILED WELDED SPLICE in the underdash harness
I can still remember finding my first. My buddies RR had a bouncing ammeter, and "in a parking lot" on a RAINY day, we had the dash cluster out, the wiring pulled out and untaped, and I KNOW he thought I'd never get it all working. But THERE IS WAS. The factory splice was BROKE. A few minutes with a "big iron" was all ti took, taped 'er up, and he was semi-forever grateful.