Allison MT653 Torque Converter Questions

[K-Unit]

Hello all! (First post so sorry if I am breaking and conventions!) (I also put this in the Chevy/GMC subforum, but there hadn't been activity there in a month, so I thought I'd put it here too!)

I have a 1977 Chevy C65 tandem. Not a bus, but I have some questions about the Allison MT653 (Same as the 643 but with the manually selected low gear). The truck is a gasser (427 tall deck) and I can't find much information on this combination online. I've seen that some people here have experience with these transmissions, so here it goes:

I have the transmission, but the torque converter is a TC370 and came out from behind a diesel. The TC370 stall torque ratio is 2.43:1, and from what I have read there was a TC350 that had a ratio of 3.09:1. So here are my questions:

1) I would assume that the gasser would prefer to have the higher ratio converter, or will the TC370 work fine?

2) If the TC350 is necessary, I have been unable to locate one. However, I found the part number for the pump assembly (PN: 2301859 for the TC350 and I can find those for a few hundred dollars on eBay. Since these converters are bolted together, can I just swap out the pump assembly to change the ratio? Was the pump assembly the only difference between the different ratios?

I do plan on hauling with it every so often to move some heavy equipment around, so that too leads me to think the higher ratio will be better. Information on these parts is severely limited online and is a couple decades before my time so any help is appreciated!