Gentlemen, looking for some help here with my transmission selection. I'm in the process of building a 500ci stroker for my 68 Charger an have made the decision that the 3 speed 727 behind the 383 I have in it now, that it that I have absolutely no history on, probably isn't a good idea to run behind the monster I'm about to drop in the K member. At first, the obvious decision was to pull that out, rebuild it and hope that it would be able to handle the 500+ ft lbs of torque this engine is destined to make. Then I got to thinking, I wonder if there is a 4 speed automatic out there, that isn't electronic so I don't have to reinvent the wheel trying to get it to work in an electronically antique car, AND that could stand up to the kind of power I plan to throw at it??? I've done some research and it would appear as though the bulletproof 727 transmissions where later named using a 4 character numonic that characterized what the transmission was. The first character being a number, either a 3 or a 4, denoting 3 or 4 speeds. The second, again a number, 1-9, denoting the torque capacity of the transmission, 1 being the lowest torque capacity, 9 being the highest. The third, being a letter, either R, T, or A, denoting Rear, Transverse, or All wheel drive. And finally, the fourth being a letter, either E or H, denoting a Electronic or Hydromechanically controlled transmission. So, with that information in hand, I determined that the best choice for my high horsepower, high torque engine would be a 49RH. A transmission that according to google, doesn't exist. So, I searched 48RH, and got some results, mostly diesel websites advertising high capacity oil pans for these units. But not many options for purchase of such a transmission and what I could find only had a tail housing designed for a transfer case to bolt up to it. Again, I lowered the second number to see what came up and again, more diesel sites and transmissions with t-case tail housings. Has anyone heard, seen or put a 4 speed, hydromechanically controlled automatic trans behind a big inch mopar? And had good luck??? Would really appreciate any info anybody out there might have. Thanks in advance guys.
First you will need an Ultra Bell adapter to put a A518 or A618 to a Big Block. A well built 46RH might do the job. The 47RH and higher are all A618 diesel units. They have lower shift points and may not work well with a 383. The only 48 I know of is a 48RE. TCI has a performance rebuild kit that might do the job in a 46RH. You will find a lot more 46s available. You will need to work with the hydraulics for the OD and lock up. Check out this web-site, http://www.transmissioncenter.net/SwapInformation.htmDon
Thanks Don, for the trouble that it sounds like it is, I think I'll probably stick with my 727 and tach 3 grand on the freeway.
Build the 727 right and it will handle 1000 hp easily. Then if you have the $$$ use a gear vendors unit ( overdrive / under drive ).
10's or bust!!