aa is about to release a 4:1 gear set for the split case......i'll start another thread on here about that. 
Can't do it with those transmissions. But I can get a H55F out oh an HZJ73 and a 300mm clutch out of a Isuzu and run that comno behind my 1HD-T so I am currently on the look out for those parts. I will also have to get a flywheel from Australia from a manual 1HD-T but I will get this combo to work.
I doubt a H55 will keep on working behind a 1HD-T. If you compare the purchase of a fresh H55,plus Clutch plus fly with that :
http://www.marks4wd.com/products/gearmaster/Cruiser-Crawler.htm
than you probably change your mind.
I also doubt that the AA 4:1 is made to fit the HF2a tranfercase.
Matt
