Rob, 37Æs would be pushing it for the D44 with modÆs?
its a grey area. you'll get answers both ways. my advise is, yes, you can run it, but if you have a moderate-agressive driving style and thirst for more difficult trails, breakage will be inevitable. If you want to be more secure on a D44 and 37's, you'll want to budget CTMs and alloys in... which you are correct, will easily take you to D60 prices... something many don't consider when comparing prices between the cheap D44 and expensive D60.

Does the coloradok5 website, which was specific to k5Æs, also refer to ¥ ton trucks, or is that something completely different?
yes, suburban's and trucks of the same years are all lumped together.

What is involved in swapping a ¥ ton-8 bolt lug pattern to a 6 lug?
basically follow the 8-lug swap in reverse. You'll need 6-lug hubs (big bearing) and caliper brackets.

Would the Isuzu 12 bolt stand up to 37's?
yes, but again, you're in that grey area I talked about before. be gentle and prepared for occasional failure you'll do fine. drive with caution to the wind and expect it to hold, and you'll be asking for trouble.

-Rob