1957 oldsmobile 371 trans replacements ???

I am still looking for a replacement for the olds jetaway. I think that all of these will bolt up to the 371 olds(without any adapters or modifications). If you disagree on any of them please let me know so i can update my search. Thanks for you expert advice. Randy

Cadillac Hydramatic
46-55

Cadillac Dual-Coupling HM (Jetaway)
56-64

Chevrolet Pickup Hydramatic
53-62

GMC Pickup Hydramatic
53-62

Hudson Hydramatic
50-55

Hudson Flashaway (Jetaway)
56-57


Nash Flashaway (Jetaway)
56-57

Oldsmobile Hydramatic used in some 1956's
46-56

Oldsmobile Dynaflow
some 53's

Oldsmobile Jetaway used in most 1956's
56-60

Oldsmobile RotoHydramatic (375) Model 10
61-64

Oldsmobile F-85 RotoHydramatic (240) Model 05
61-63


Pontiac Hydramatic
48-56

Pontiac Strato-Flight (Jetaway)
56-64

Pontiac RotoHydramatic (375) Model 10
61-64

Willys Hydramatic
54-55

 

You seem to have most bases covered. The only information I can add is as follows:

1) You will need the "rear" bell housing for any of the single range hydramatics. I believe this is also true with any of the Jetaways.
2) If you decide to use the single range hydramatics, use Cadillac, Oldsmobile, or Pontiac models from 54-56. Note: Cadillacs only used them till 55. The reasoning here is that the later single range hydramatics have 8 clutch plates in each of the internal clutch paks. Hudson, Willys, and any used with 6 cylinder engines will have less clutches, therefore less durable.
3) If you use single range hydramatics, you will need to drill out the back of the crankshaft for a pilot bushing. You will also need to counterbalance the hydramatic flywheel to the 371 crankshaft.
4) Jetaways, whether Olds, Pontiac, or Cadillacs are for the most part the same trannies. (Why would you want to use one if you want to change)
5) Using the 53 dynaflow (due to hydramatic plant fire) or the Roto hydramatic (slimjim) is not a good idea. Neither is a very good transmission.6) I don't think the F85 roto hydramatic will bolt up, as it was used on 215 aluminum V8's, not the 303/324/371/394 basic block.

I suggest using the single range hydramatic out of a 54 or 55 Olds. This will have the bellhousing, heavy duty clutches, and (other than not having a true Park position) should adapt easily to the shift linkage and TV linkage.

(I have done the engine/trans hookup, just with a '60 371)

Hope this helps

 

56-60 Olds, Pontiac, Caddy should be the direct bolt in for a '57 Olds car; 61-64 Caddy and Pontiac Bonneville/Star Chief (long wheelbase cars) will be the next closest. Some of them may give you an extra gear position. But if you're looking for ease of install, that's what you want. I have a core for one of those but I don't know that it's any good.

 

So i think i have this narrowed down to these options, Sorry to be a pain in the ass but i live on an island and the closest mainland is 1 hour away and getting parts is a bitch so i need to make sure it will fit. Thanks for the help. i will start shopping for one of the following.


single range hydramatic out of a 54 or 55 Olds.

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56-60 Olds, Pontiac, Caddy should be the direct bolt in for a '57 Olds car