'53 GMC factory automatic compatibility question...

[MrTucker]

I'm pretty sure I know the answer, but I'll ask anyway...


I have a 1953 GMC that is all orginal with a 228 straight 6, with a Hydramatic auto tranny. Both ran when the truck was put into storage. Check out the link in my sig for the full story.


My question is what (if any) other engines will bolt up to this tranny? Specifically, will a 235 bolt up? There's one down the street from me that's been freshly rebuilt and painted for next to nothing.

I plan on doing an S10 swap, 350/700R4 swap - but I'm curious and cant find the answer....

[Steve@OldSub.com]

I don't know the complete answer. Part of it though is that GM did some additional work to match Hydra-Matics to engines so while the bell housing will bolt up it may not be within spec.

But its been done and worked out.

That's the part I do know, what I'm not sure about is whether the part that bolts to the crankshaft will be the same between the 228 and the 235. GMC used a couple of different crank flange patterns over the years and I seem to remember that all the Hydra-Matic versions are one of the two types. But I don't recall which and it may not be the same as the Chevy.

But since starting in '54 Chevy pickups were available with Hydra-Matics the right parts to adapt it are available.

If you're '53 GMC with Hydra-Matic is all there and will run you may find it has some value to a collector. Its the first year GM put an automatic in a pickup and because of production problems they are rare.

I have a '54 GMC with Hydra-Matic that barely runs and the transmission works but is clunky. It bothers me to think of taking it apart and separating it all, but I'll probably be doing so sometime in the not too distant future.

[MrTucker]

I knew you'd have something to say....

Originally Posted by Steve@OldSub.com

...But since starting in '54 Chevy pickups were available with Hydra-Matics the right parts to adapt it are available.

That's what I was wondering - I know there are Chevy's with Hydramatics, but as far as I know they are 235's. I wonder how I can figure this out, without buying a 235...

Originally Posted by Steve@OldSub.com

If you're '53 GMC with Hydra-Matic is all there and will run you may find it has some value to a collector. Its the first year GM put an automatic in a pickup and because of production problems they are rare.

I have a '54 GMC with Hydra-Matic that barely runs and the transmission works but is clunky. It bothers me to think of taking it apart and separating it all, but I'll probably be doing so sometime in the not too distant future.

Welcome to my struggle! My '53 is 100% original, and I'm only the 2nd owner. My wife's great-grandfather bought the truck brand new in '53 and it's been in the family ever since. According to my father-in-law, it was in good running condition when parked, 32 years ago. He said his father drained all of the fluids when he parked it - and that worries me. What are the possibilities the engine/tranny are even any good? I'd love to rebuild them both and run the truck in stock trim, but that would cost a small fortune - I assume.

Do you have any info on 228 rebuilds? Or Hydramatic rebuilds?

[Steve@OldSub.com]

Originally Posted by MrTucker

My wife's great-grandfather bought the truck brand new in '53 and it's been in the family ever since.

If I had a story like that to tell about my Hydra-Matic I'd restore it myself. Mine I bought for $500 from a guy who gave up restoring it after five or ten years of getting very little done. Mine is going to be a hot rod.

I'm not the guy who rebuilds GMC sixes so I don't know many of the details you're after. If no one here offers more help try the forums at OldGMCTrucks.com. You may be able to find the Hydra-Matic and crankshaft details with a couple quick searches.

While the 228 cost more than a 235 to rebuild it isn't bad. If the part of Colorado its been stored in is dry the motor and transmission may be fine with the addition of lubricants. I'd at least try to run them before assuming they need major work.

Faced with your dilemna I'd probably look for one of the bigger GMC motors. The 270 and 302 make more power and are more desirable than your 228 or the next motor, the 248. Its not hard to make a 270 or 302 look just like a 228 so only the most knowledgeable would ever know you'd changed it.

Building one of those motors will take more work and more money than a cheap small block or even cheap 235. But if you are thinking performance crate motor that budget should more than build a big GMC.

The challenge with the Hydra-Matic is finding someone who knows how to do them. I know a couple of guys who have had them done over the last couple of decades. In each case they found an old guy who had done them back when they were common. Guys who did transmissions in the 50's and 60's and who are still willing to work are getting rare...

That doesn't mean it can't be done, nor does it mean you can't do it yourself, its just a little more challenging.

My grandfather had a '41 Chevy 1-ton truck. If I knew where that truck was today I'd be chasing it hard and wanting to restore it. I suspect that truck has made more than one trip east as scrap by now, since he sold it in the 70's and though he never admitted it to me, I think he sold it as scrap.

Even if the in-law nature of your relationship to this truck's history doesn't move you to restore it, the rarity and first of its type nature should at least make you consider carefully before going too far from original.

I say all of that knowing if it were my truck I'd do whatever I wanted and would not care too much what you thought. Its your truck make sure what you do with it satisfies you.

[MrTucker]

I hear everything you're saying. I love old original trucks, just as much as hot rods. If I decide to do an original build, I wouldn't expect modern performance. I'd more than likely upgrade the brakes, but running a 228 would not bother me. I know I'd never break 65 mph (hell, probably never break 55, ), but that's the fun of it. I want to keep it close to completely original, but not interested in doing a 100 point resto...maybe in the future.

If this were just some truck I bought off of Craigslist I'd gut it, slam it and make a hot rod. But this isn't just some truck. Plus, this thing is pretty rare - I'm not sure how many hydramatic 53's were made, but I have yet to see another. I'd love to keep her stock, but for what it will cost to get her there I could build a hot rod, twice...maybe 3 times.

Heck I dont know...ask me next week and I'll want to do something totally different.

[RONB54]

You will have some problems with the engine mounting in the truck because the chevy engine is much shorter . The front mount does line up and the could be problems with fan/water pump alignment.