automatic transmission in a P15

[james49ply]

Has enyone thought of installing a 60's Oldsmobile transmission? The 'Slim Jim" does not have a converter and uses a dampner plate that looks like a cltch disc but is bolted directly to the flywheel. The input shaft is multi-splined and slids into the dampner plate. The trans is also called a "Roto Hydromatic" I wonder if this would provide better fuel economy as it has no converter to slip, thus giving you an automatic without the weight and slippage of the converter. Just pondering as I am working on rebuilding the engine on a 64 convertable.

[40P10touring sedan]

James, are you running the flathead 6 in that sedan? If so, and you plan on staying that way, there's few options for "other" automatics for flathead 6 owners aside from later model oem trans'. Wilco makes a nice adaptor to mate up a 700r4 behind a flathead 6 and there's one other company that makes the adaptor to put a torquflite 904, 727 or modern A500{and equivelent} behind a flathead 6. That's it so far as I know of...

[greg g]

Wonder why you would want to back to 60's techology that is likely not very supported ( and it wasn't a satisfactory unit anyway) when you can get adapters to put a modern OD automatic in. The !st thing I might look for if you want to go retro would be a Powerflite trans from a 54 or newer MoPaR. They were very trouble free, and gave decent performance.

[Tim Keith]

Consider a 200R4 and a Wilcap adapter. The parasitic losses of this transmission are lower than most because of its internal design. Its also smaller and lighter. The 700R4 has high internal power loss that would zap a flathead, its much heavier duty than needed. The 200R4 can handle a V8. I'd go with a T5

[wayfarer]

James, are you running the flathead 6 in that sedan? If so, and you plan on staying that way, there's few options for "other" automatics for flathead 6 owners aside from later model oem trans'. Wilco makes a nice adaptor to mate up a 700r4 behind a flathead 6 and there's one other company that makes the adaptor to put a torquflite 904, 727 or modern A500{and equivelent} behind a flathead 6. That's it so far as I know of...

The other company is Quality Engineered Components

The 727 is NOT recommended due to the higher parasitic losses. The 904 is reputed to have similar losses to the small gm units but there is very little hard data from which to get actual hard numbers.

Keep in mind that with a late model trans swap there will be a substantial amount of 'incidental' work.

[Tim Keith]

The most efficient transmission might be a two speed aluminum Powerglide. Even though the Powerglide was first used in 1950 it has good aftermarket support, but I don't hear of anybody using them except for racing. I don't know how the efficiency of the Powerflite compares to the popular GM two speed, but those iron Powerglides are heavy. The A727 and 700R4 are inefficient - they are best with big blocks, they waste too much power. The A904 is reasonable and its light too. The A500 overdrive is based on the admired 904, but its not as well regarded. The parasitic losses of the Powerglide are the lowest. Because the Mopar auto overdrive are not well regarded some are using the 200R4 for its compact and efficient design, although it was designed for fuel economy it can handle 1000 HP with aftermarket parts. Some of the slant six drag racers are converting to the 200R4.

[james49ply]

thank you for the input, I was thinking of that trans because I have one out of a 64 98. looks like the way to go would be the 200r4.

[montego8]

O.K guys,I have a question about this subject and can't make up my mind. I have a 50 dodge with a bad motor. This car has a three speed fluid drive. The transmission also has seen it's better days. I just bought a flat 6 from a 58 Plymouth with 21,000 original miles on it and the guy threw in the transmission. I was going to use the old three speed ,but then I though about getting a adapter and going with a modern 5 speed or OD transmission. But I have this low mileage 58 two speed push button transmission that ,of course , will bolt right up! Now I know my cars transmission mount is to far back,but I can alter that. My question is, were these transmissions any good? Will the car be more of a dog out of the hole and at what rpm will I be at driving 60? Boy any thoughts would be great. Also ,I just got the transmission, not the shifter. There are two ,well three cut off cables on it. One is for the e brake the other two well? One must shift and the other mush be the kick down. I don't need to use the kick down,if that is what it is, but the cable that shifts it,does it just pull in and out or is there something special about how the push button shift works?

[Plymouthy Adams]

should have gotten the rear end also..I know in my 54 with two speed auto and the factory 3.73 it is not the dog off the line my original 49 Plymouth stock set up...plus consider the shifting..how many of you are in third gear before 53 MPH?..the point the 54 will shift just by holding the pedal down..the real thing you must consider..at what level of modification are you willing to go for your car..

[greg g]

Some powerflites were shifted by a cable affixed to a dashboard mounted to the dashboard, similar to the system that the Corvair used. The powerflite was a good simple trans that provided the basis for the torque flite.

http://www.allpar.com/mopar/powerflite.html

[Plymouthy Adams]

the Powerflite continued to be produced alongside the torqueflite for I think 6 years which speaks highly of the transmission. I bought the 54 though not looking for a project..a gentleman came by the house letting me know he has a car that I may be interested in..it had all the right features though was the patina queen..unmolested, two door, high trim line, atuomatic transmission...and the price was right..

[montego8]

The older I get the less I'm interested in modifying cars. I liked the way the car drove before the motor blew.I'm just not sure the transmission has much life in it and I got this low miles two speed. Is there a way I could tell which size rear is in my car?

[55 Fargo]

The older I get the less I'm interested in modifying cars. I liked the way the car drove before the motor blew.I'm just not sure the transmission has much life in it and I got this low miles two speed. Is there a way I could tell which size rear is in my car?

What year and model is "your car"?

The diff ratio, will be stamped on the 3rd member(pumpkin), unless gears were changed internally.

Mark 1 tire, mark drive shaft, rotate (roll) car, count revolutions on driveshaft to 1 revolution of the tire. IE tire rolls 1 revolution, driveshaft spins 4 times, diff is 4to1 or 4.00 gearing....Good Luck

[40P10touring sedan]

The older I get the less I'm interested in modifying cars. I liked the way the car drove before the motor blew.I'm just not sure the transmission has much life in it and I got this low miles two speed. Is there a way I could tell which size rear is in my car?

...you may be lucky and have the ratio tag still bolted on the pumkin, but alot of those rotted away, were removed or were never there to begin with.

[40P10touring sedan]

As you may know from earier here in this thread, I'm planning on installing a 2004r{correct desrciption} auto trans in my 40 ply....while I still have to find one I just came from Lokar's site and they not only have floor shifters for that model trans in various heights{and chrome or black finish as well}but a universal TV cable set that could be used for our single and multi carb usages.

I'm looking at Goodfellas transmisions on ebay...yeah, the girls are nice too...as his set up has quite a few options to go with and the price isn't far off from anything else I've seen.

I still have to figure out what stall would be good for my 265..1300 or 1500 area should be good I'd figure....thoughts...