I'll answer my questions for future reference....
I have been searching but I cannot find the information I need.
I am stuffing a 1KD-FTV 3ltr Hilux engine in my 88 4Runner, and while I am doing that it will be time for adding the dual case setup to the trans.
1. Does anyone know what the spline count is for the Aussie R151(production date 2006? 23 spine just like the R150
2. Is Aussie R151 tailhousing the same as a +95 Tacoma R150? not sure but the pre-95 R150 has a differnet housing
3. I think the Aussie R151 output shaft is 23 spline, my t-cases are 21 spline, is it possible to change the v6 to 1st case adapter so that trans side is 23 spline and the r1FA is 21? (I'll upgrade to all 23 spline later when I can afford the 4.7) See question 1
4. Hopefully I can pull off the 5th gear swap using an R452 5th gear for increased overdrive..... this seems to be working.
Installed R452 5th gear on a 2006 R151f transmission!!!!
and the rest of the mess, two R1FA transfer cases Inchworm Doubler adapter and an Inchworm R150 to R1FA adapter.
Replacing a few bearings while I'm in there. Can't wait for lo-lo behind an idling grease burner.