1958 hydramatic to th350/th400 swap

[Rdtreur]

I got a 1958 motor and transmission in my 1952 coupe . The '58 hydramatic is beyond repair here in the Netherlands  (shifts only 1-2 ) . So I want to swap it to a upgraded th350 or stock th400. I wil most likely use the Wilcap adapter.
Now my questions:
1: Are there any members here that did a swap and can give me advise?
2: what is the best replacement: long tail vs short tail th350/th400
3: What are the dimensions of a old hydramatic vs th350/th400

Any advise would be appreciated.

Many thanks, Ramon

[The Tassie Devil(le)]

G'day Ramon,

Once you have solved the transmission swapping problem, your next problem will be the Gear Shift Indicator and Neutral Start Safety Switch, and lack of Reversing Light function.

I had a TH400 in my '60 CDV, and the previous owner simply repainted the lettering and numbers in the indicator quadrant, but did nothing about the Reversing Light function.

Bruce.

PS.   My cad had a 454 BB Chev in it.   It fitted well, BUT, the lack of combined weight of the later engine and trans really showed up when I reinstalled a 390 and Hydro.   I couldn't believe just how nice the car drove with the "normal" weight, plus it was a lot smoother with the really low gearing of the 4 speed. 

[bcroe]

I got a 1958 motor and transmission in my 1952 coupe . The '58 hydramatic is beyond repair here in the Netherlands  (shifts only 1-2 ) . So I want to swap it to a upgraded th350 or stock th400. I wil most likely use the Wilcap adapter.
Now my questions:
1: Are there any members here that did a swap and can give me advise?
2: what is the best replacement: long tail vs short tail th350/th400
3: What are the dimensions of a old hydramatic vs th350/th400

Any advise would be appreciated. Many thanks, Ramon

My own biased thought, is it might be a lot easier to put in a complete
70s V8-TH400 package than to use a trans adapter.  My experience
with some of the earlier engines was pretty much bad, and they were
not happy with todays low octane unleaded.  By late 70s a more
powerful, much lower maintenance, unleaded V8 engine such as Cad
425 or Olds 403 were available. 

As I recall the drive train mounting was quite different in 52, check how
much fabrication would be needed to mount a conversion to the body. 

My pick is a dirt simple TH400 which was available in 3 lengths, FAR
stronger than a TH350 with no expensive upgrades, parts everywhere. 
Could be had as a switch pitch, for extra performance and economy
when electronically controlled as a 6 speed.  Either has so much more
torque multiplication at launch, a good match up would involve reducing
the axle ratio from 3s to 2s.  The TH400 control is 12V, what is your 52? 

The above use a slide in drive shaft yoke, is yours bolted into the
trans rear?  Most likely a new drive shaft is needed, there is a truck
version TH400 output that bolts in for multi piece shafts. 

The shift pattern and starter safety switch are about the same for
TH350 or TH400, but completely different from the 50s hydro.  The
connections to the carb linkage will be different for a TH350, gone
for a TH400. 
good luck, Bruce Roe

[Roger Zimmermann]

Your transmission can be overhauled (I did about 30 Hydramatic); it will cost less than a radical change...

[Rdtreur]

Your transmission can be overhauled (I did about 30 Hydramatic); it will cost less than a radical change...

I can not find a decent rebuilder that want to do the job and give me a warranty on the job or any guarantees that it wil shift like it should. I got a quote between €2000 and €2500 with no guarantees.... I think the swap will be a beter option:-(

[Roger Zimmermann]

Not sure if the swap will be less costly. After all, it's your car...The price you got is not excessive compared to a similar job done in Switzerland by a good transmission shop. I do that for about half that price, but I'm not a professional even if I'm working better after what I saw on transmissions freshly rebuilt by some professional companies...