the inner joint isnt the issue on out cv's its the outer joint thats a big POS!. The only difference between our cv joints is really the length. Total chaos designed their kit to use stock tundra cv's in a tacoma. However they sell "modified tundra axles" and this really gets people confused. All they are doing is machining the edge off the inner tulip so the inner will not bind at full droop with Long travel. What they dont tell you is this makes about a 1/2" to 3/4" difference in where the droop binds the cv. With long travel you are supposed to run limit straps so if you strap it 1/2" sooner you can just user regular tundra cv's which cost about $90 each.... I would sacrifice that 1/2" of droop for $180 per pair of cv's compared to TC "Modified axles" which are about $1000.
THe tundra front diff is that exact same as ours... Same spline count (27) and everything. Who cares about that inner joint. Its a good design on 4runner/tacoma cv's. I have never heard of someone breaking the inner joint. Its always the outer or the shaft breaks off in the diff. THe real issue is the junky race on the outer...
As as far as a tundra axle in the back. Sure it will work. But what do you want to do? Run leafs? Move the gas tank and 4 link it? ANything can be done but if you just want a stronger wider axle i would suggest looking for a ford 9, dana 60, toyota 9.5 (80 series lc rear end), corp 14 bolt. Cutting the stock 4runner brackets off the axle on putting them on a different one is alot of work you will get better results completely ditching the stock rear suspension. Want an easy swap? Use chevy 63 leafs and chop all the other brackets off. IMO a 4link is easy enough to get half decent numbers on our trucks with straight lowers About 36" long and uppers about 35º slightly shorter. If you want to go that route get the 4 link calc and play with it.
Good luck
