Would advance adaptors make an adaptor for a Perkins
The stuff above would mate a Range Rover gearbox to your engine but its made for a manual gearbox so like Scrw says you would presumably need a flex plate drilling and then you would have to either use the Rangies transfer box and get rid of the seperate one or get rid of the Rangies transfer box and fit some sort of drive coupling to the auto box.
I have no idea how strong the Range Rover stuff is either, it may not last 5 minutes with that engine and hulking that thing about but the same may be said of the TF999.
The trouble is whatever you do it means having something engineered somewhere and if you dont know anyone and cant draw what you want precisely you are wasting your time and are better off just sticking to the manual box or finding something else with an auto box already
Dont you have any spare AMC V8s anywhere?