Now the 4R70W parts into an AOD. Yes it can be done. Gets you 2/3's of the way to a 4R70W. Costwise it comes in nearly the same as you now need 2 transmissions to start with and rebult one with half the parts from the other. It will get you some of the benifits of the 4R70W (wider band, gears, mechanical diode) but you still won't get some of the better aspects of the 4R70. You can't control the lock up of the converter, you can't dial in each of the shifts, you can't hold 2nd gear (without another costly upgrade to a new custom valve body). So there are several limitations to doing the reworked AOD.
sorry to hijack a bit
Please expand on this a bit.. If i stay with an auto vs manual I am torn still between a auto (aod or 4r70w) mainly as i want to have a manual valvebody and strength with no electronics and from i have read the aod just dont got it in the strength department. Reason for the manual valvebody is i have a c4 now and shift it, i have all the automatics i have owned dont know why...
currently have:
302, dana 20, 350 gearing and 31's
will be upgrading to
351 , dana 20 4.56-4.88 and 35's