As said, an AOD will be your best bet if you want overdrive. Get a later 4r70w and a bauman tcu, then you will need a custom bellhousing/converter and probably driveshaft; they are a nice box and have heaps better ratios then the BTR.

the only time i'd use an AOD is if it was a full manual with a constant pressure valve body.
the variable pressure valve body you have to use to retain the auto function is a PITA to get the cable geometry right when used in a none factory application, and need checking and adjusting every 6 months or so. getting the line pressure wrong will mean death to the AOD

Do AOD suck power like the FMX boxes???

Last edited by MICKYYYY on Mon Oct 19, 2009 2:15 pm, edited 1 time in total.

Well if the OP is making enough power to warrant a TH400 installation, then I'd guess $2500 is cheap.

What about some of the overdrive automatics used in sport compact racing? I know a guy that has built a few and he reckons the difference between those and an old school C series box is night and day.

TH700 through my box builder is $5500-6000 that includes converter, B&M pro racket shifter, oil cooler & lines everything installed.

Or like my old C4 is $5500 that includes converter, B&M pro racket shifter, oil cooler & lines everything installed plus over drive

Or a AOD from Performance Automatic in the US for $3700 plus everything else so a tad over $6000

Which boxes are u talking about that are used in sport compact racing and that are night and day compared to a C series box???

I'll have a talk to the bloke next time my car is up for a transmission service.