hydramatic conversion (54) any tips?

[SouthShore54]

i am looking to convert my '54 to hyramatic...already have the colum with auto shifter, and a i have a line on a hydramatic trans converter and flywheel.

other than the rear and drive shaft, are there any other hydramatic only parts that i need? is the trans x-member the same for manual and auto?


Does anyone recomend a good rebuild for the old hydramatics?

Thanks, Mike

[5Mike7]

Pretty sure you'll need a new X-member...are you planning on using the old GMC 4 speed Hydramatic or newer like a TH350/400?

[SouthShore54]

if possible i want to use the original '54 hydramatic 4 speed..i have one tracked down, but waiting for seller to get back to me.

[5Mike7]

They were not known for longevity, unless your truck originally hd one and you are planning on a correct restortaion, you would be better off with a newer Od tranny...just my opinion.

BTW, was the 4spd hydramatic trany OD? I recall a buddy of mine wthe a 56 or so GMC wth one in it..but don't recall if it was OD or not.

[SouthShore54]

what will it take to bolt up a th350? i wanted to keep it all original ('54 parts) but if the original hydramatics arent so great than i really dont want to waste my money.

do you know of a good source for parts interchange information? if i am going to upgrade the trans i would also want to change the rear to a more modern set up.

Thanks, Mike

[5Mike7]

What engine do you have in it now? There's adapters for evrything, but new they are pricey.

[SouthShore54]

i have the original "big 6"

[5Mike7]

Hmmn, You might try Stovebolt to see what can be adapted easily, and another good place would be to try inliners international.

There's another place that deals in inline performance...Clifford Perfromance..they may know about some swaps for you.

For adapters, google wilcap ...theyve been bought out by someone else I think, but I did find them on the web before, when you find the site it will list many adapters like Ford to DOdge, etc...once you get the p/n (assuming they have what you need, you can search many of the online auction/swap meets and see if you can find a used one.

[5Mike7]

Here's an older GMC site, you night get more information from:

http://www.oldgmctrucks.com/

[Gene Sharp]

To the best of my memory :
This was essentially the same trans used in the Oldsmoblie cars of the same era
It was a 4 speed auto with a low first geat to get it all rolling and a 1 to 1 fourth gear ......Worked pretty well !
The difference in the Chevy and Olds units being in the housing that attached it to the motor
They were pretty stout ,,,,,,a lot were used in early race cars ( I think some were called Hydro stick)
many converted to a manual valve body and a "stick shift " thus giving a 4 speed auto at a time when all 4 speeds were rare
With a good rebuild should work
you may need to check up on what rear end gear to use


Gene Sharp