The Stovebolt Site Forums The Shop Area Driveline Power Glide Compatibility

I have a Power Glide Trans. from a 56 Bel Air and want to connect it to me rebuilt L6 250 engine. Will that work? Will the PG bolt to the 250 block?

You would need an adapter ring from an early V8/Powerglide vehicle. I don't think they made a different transmission case for the V8's, and the 6 cylinder models definitely used an adapter. It's a cast iron adapter about 2" thick on the 6 cylinder models, but that one will have a different block bolt pattern than the 8 cylinder. Your 250 has the same bellhousing bolt pattern as the early v8's did.

A cast iron Powerglide would be the worst possible choice of automatics for most uses. Any reason you're choosing that one?
Jerry

Thanks for the info Jerry.

I already have the L6 250 engine and the cast iron Powerglide transmission. I'm restoring a 56 Bel Air and know that the 6 cyl. used a Powerglide. That's why I thought they wold be compatitable.

If I went out and bought a used automatic trans. for the 250 L6, what would you recommend?

I would get a TH350 if I were doing it.

The simplest choice would be a TH 350 with a Chevy bolt pattern. It's a direct bolt-up to the 250, and since the 350 was a factory option for untold thousands of 194/230/250 engines, there are plenty of OEM parts available. It's a 3 speed with direct drive in 3rd., the same final drive ratio as the PG, but with 3 speeds instead of two. If you want an overdrive, the 700R4/4L60 (same transmission, different name) and they're also pretty plentiful, as a lot of the S-10 pickups with 4.3L V6's used those transmission.

Other options would be a TH400 with the Chevy bellhousing, and a TH 250 (not really a good choice!).
Jerry

Ive never heard of a different bell housing being used between a chevy 6 and a v8,maybe Im wrong.

Yep, you're wrong. All the 216/235/261 6 cylinder engines from 1936 to 1962 used a different bellhousing than the V8's, which didn't even exist until the 265 came out in 1955. The 1962 Chevy II 194 sixes and the 4 cylinders used in that car were the first one to use the same bellhousing bolt pattern as the V8, also the 1963 230 sixes in the Chevelle.

Dad-blamed young'uns!

Jerry

Thanks Guys...this is very helpful. Suggestions on where to get a used TH350? Junk yard, or transmission shop, or private party? Other?

The junkyards used to be full of 'em. You might also check your local transmission shops to see if they might have an "old stock" rebuilt 350 on the shelf stashed away that they'll sell for a bargain price. Too bad you're not a little closer to Tennessee- - - -I've got several cores stashed away and I can practically rebuild one in my sleep!
Jerry

I thought he was talking about a 250 6 cyl though?

He's talking about adapting a Powerglide from a 1956 BelAir to a 250. He did not mention whether the PG came from a 6 cylinder or a V8. If it's from a 6, it would have had the adapter ring for a 235. If it happened to be from a 265 V8- - -AND- - - -the adapter ring was included, he's good to go. Either way, it's a whiz-poor choice of transmissions when so many better options are available.
Jerry

Jerry,

My 56 Bel Air has 3.36 rear gears. If I put a TH350 tranny in, should I keep the 3.36 rear end? Or switch to 3.55 or 3.75. Most of my driving is around town with occasional longer highway trips.

The 3:36 rear end is the factory ratio used in a 56 car with an auto trans. Since the 350 trans is still 1:1 in 3rd gear the final drive ratio wouldn't be any different than using the stock PG trans. In my opinion the 250 engine would be fine with the 350 trans and the 3:36 rear end for your stated driving needs.
Fred

The 3:36 should make for a nice driving car

The 3.36 is a good gear. I liked the 3.70 rear end that the 6 cylinder 3 speed cars had, for a little better acceleration, but it did reduce gas mileage a little. My 58 Delray coupe with a 283 Corvette engine and a 3.70 was a sleeper, since I kept all the 6 cylinder chrome on it. I embarassed a few wannabe hotrodders with that one, and collected a few speeding tickets back in my wild and wooly youth!
Jerry