Im building a 30 model A coupe a slick car metal flaked. I’m running a 392 Hemi. I’ve got a Powerglide new heavy duty built or a T350 that I will have to rebuild. Can’t decide which one I want to run. Looking for some help. Pros/ Cons
With that light car and the torq you'll have, the glide would work. Don't know the HP but both would need beefing up.
I would love to run a powerglide in something just for the novelty of it. But, for your application your probably going to want to run the 350. Just because everything is available to make them work in almost anything. They are probably the overall best automatic arguably. I have a 700r4 in the red StreetRod car because it was in it there when I got it but I would have run the 350 in it if I had built the car.
2 -vs- 3 gears. V8 Powerglides used a 1.76:1 low gear with a 1.00:1 high and 1.76:1 reverse gear. They use the same 27-spline output shaft as T350, 200R and 700R. Overall length is the same as T350 (Short) so there is no driveshaft modifications. T350 uses a 2.52:1 low gear with 1.52:1 intermediate and 1.00:1 high with a 1.93:1 reverse. Powerglide uses less power (18hp) due to lighter rotating mass when compared to T350 (36hp). A glide is efficient especially in regards to what they can transmit power wise. You still need to factor in your rear axle ratio, weight of car and torque convertor. If you want to go fast these are from Dick Miller's How to Hook and Launch. Starting Line Ratio (SLR) based on stroke and weight and yields the recommended SLR.
Thanks for the info. and comments. Not wanting a speed demon. Just something to play in redlight to redlight. And occasionally a trip and hour or two away.
Powerglides get little respect here (I'm referring to aluminum case (ACPG), not the old iron job that is waaay obsolete) But I think they have a place in many builds. People seem to forget the ACPG was successfully used behind 409's and in big block Corvettes in the '60's. A car with lots of torque relative to the light weight you propose would work well with the PG. The tranny is lighter, the horsepower absorbtion is less...and you already have it.....what's not to like? Ray
Ray, What's not to like is the PG will feel about a half second slower in the quarter, even though it may be just as fast or faster
yeah..well..I'll take your word for it....but to me and probably a few others, that's not such a problem. My tired old ass can't discern a half second in a quarter mile unless I am watching the taillights of the guy in the next lane who is a half second faster....IF there was a guy in the next lane... Ray
Powerglide, I have one in a 30 coupe. It runs out great. Not sure of my rearend gear, but the car was built in the early 70s. Its killer though, and will still get down the hwy with ease.
The aluminum Powerglide will actually be stronger than a TH350, just missing that extra "gear". The TH350 has a somewhat weak sprag assembly, that if it is not addressed (34 elemenet TH400 type sprag or mechanical diode), will probably be a problem at some point (when they break, the entire trans /converter has to be gone through). But, Powertglides are just plain boring on the street! I'd probably however, still go with the Powerglide. JMO. I am Butch/56asedandelivery.
More gears always = more better. Better use of available power, AND more efficient use of fuel (provided that you have the correct rear gear for weight and cruise RPM, in respect to tire diameter). My Falcon has 6 forward gears.
They are both great options. My buddies and I used to beat the crap out of powerglides back in the early 60s, and they just didn't fail. With all that torque in a light car, I would opt for the heavy duty PG, just because it is lighter and you will get more power to the back wheels at no extra cost. It really just depends on whether you would want to rebuild the TH350 with a kit. Bob
You will have to update the sprag as mentioned in the 350, it doesn't take much HP to break the original. I had a 350 in my chevelle done by a friend that built all my PG's in my dragster, worked great and I was hard on it. He's doing one now for my 28.
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