i just went through this research phase and can find the thread but let me condense it for you.

GM engine with 60 degree bolt pattern will bolt to 96 or newer 5 speed from tacoma or 4 runner (R150F series C), via 99 or newer 2.5L dodge bellhousing. This trans comes equipped with a chain t-case so you have to buy the marlin adapter to bolt it to a toy gear driven case. This setup needs a toy clutch disc with GM flywheel and GM pressure plate. Throwout bearing, pilot bearing have to be customized to work. I'll be doing this next month so maybe we can figure out at the same time.

The other trans option is NV3550 from Jeep, but it is pricey $1000+, the AX15 from Jeep, pricey also and no adapter for Toy gear driven cases, or the Toy R151F from the 4 cyl turbo 87 pickup. very rare and expensive. I have heard however the R151F cannot use Dodge bell because it is a "short" input shaft trans and doesn't have the length the R150F has. The plus side of the R151F is it does not need an adapter to run toy gear driven cases. The W series Toy transmissions, along with all other 4cyl Toy transmissions excpet teh R151F are to be avoided because they were not built for V6 power.

With all that said I went with the first setup but still gathering parts to bolt it all together.