Muds a good place to start, I know you will need to outboard your spring perches to accomodate the wider axles.
I have read, and would agree that 44s are the same strength or a bit weaker than the stock toy axles. Upgrade the birfs to longfields and be done with it.
The centered rear axle is a tricky spot, but very early cruisers DID have centered rear axles with a passenger off set transfer case. It looked a bit goofy but it was done, and worked.
The other consideration is the length of the chevy stuff. you will need like a 10 inch drive shaft for the rear which is a custom job. then another custom front shaft.
I dont know if those facts alone would be worth the hassle and cost. you will have opened the door for any parts for the engine, trans and transfer at any autodrone store, but have customized the driveshafts to the point where it would be hard to get replacements cheap.
Most have done a 350 conversion and used an adapter for the stock trans and transfer. You have small block power and parts availability. but keep the rest Toyota. Where you can still find parts, but gotta pay a bit more.
Your arguably decreasing the value of the rig too with all chevy stuff.
Just my .02