overdrive trans?

I've been toying with the idea of using one of the newer overdrive trans in my 40. Not sure if I really need one as I'm pretty sure the gearing in the rear is high numerically(out of 79 LeBaron). If I can use one how are they operated with out the computer? Are they any longer than a 904? thanks later shawn

An A500 or 42RH is about an overdrive unit longer than an A904 and the A518 or 46RH is about an overdrive unit longer than an A727. Any of the trannys older than 96 are hydraulically shifted. 96 or newer thay require a computer to shift such as a 42RE. The older ones the only electronics is to operate the OD and lockup functions. There are instructions on using pressure switches to do that. I think I have a link to them. Go to the last part of this link.
Bryce

tranny info

If you have a 2.2, 2.45 or 2.76 rear gear an overdrive will be of little use, it will drop the engine RPMs so low that it will be lugging too much -- low engine efficiency and possibly not enough engine power at those RPMs to overcome rolling and wind resistance.

You didn't mention what engine you'll be using, but an A999 (the wide-ratio version of the 904) with a lockup converter would make a good inexpensive match with those highway gears.

What's your goal for the car? Hotrod or cruiser? What's your budget? Give us some more background and we can get more specific. A person can spend a lot of money on fuel-saving components that take too long to pay off.

I have the 518/46RH in the 36. With a 2.76 rear the RPMs would drop to 1000 on the highway in overdrive, impossible to use on the street. Changed up the rear to 3.55, no problems. I did the pressure switch system shown on PATC website.

http://www.transmissioncenter.net/SwapInformation.htm

I'm using the 318,904 and rear out of a 79 LeBaron. I guess the newer overdrives are out of the question as I already have the trans mount welded in. The car is basically going to be a cruiser, maybe pull a 13 ft single axle camper if I get one, budget is really tight(laid off). I'm a u-pull-it kinda guy. I believe the 904 that was in the LeBaron has a lock-up converter, not sure as I haven't seperated the motor from the trans yet. I need to rebuild it anyways as my dad forgot to hook the kickdown linkage back up when he put the new carb on and smoked the low, reverse band . What did the A999's come in? Thanks later shawn