The Stovebolt Site Forums The Shop Area The HiPo Shop 700R4 trans w/ 261 ?

Well, my wife isn’t comfortable driving my ‘50 3600 with the T5 tranny. I love the T5, but to get more utility out of the truck, I think I’m going to need to put an automatic behind the 261…. And an overdrive gear will be needed.

I have seen a few different adapter plates for the 216/235/261, and at one time I see the Langdon even had one available.

What I am wondering is if anyone has managed to put an automatic behind a 235 or 261 while keeping the rear engine crossmember, or is it simply impossible for an automatic trans and the rear engine crossmember to co-exist in the truck?

I really don’t like the idea of removing that crossmember…but perhaps there is no other way to do it?

All of the conversions that I have seen with an OD automatic have converted to side motor mounts and a matching transmission crossmember.

The 700R4 in particular needs to be supported at the tail because the case has a tendancy to crack if unsupported.

If you're going to go to all the trouble to adapt an OD transmission to a stovebolt engine, RUN- - - -don't walk away from the 700R4. The 4L60 is the same mechanically as the 700, but it's got electronic shift controls instead of a TV cable. You can buy a stand-alone computer to control the shifting, and avoid all the hair-pulling nightmares of trying to get the length of travel and rate of movement of the TV cable correct. Of course, a much better option would be to adapt a Ford AOD to the stovebolt engine instead of anything GM has to offer.
Jerry

I had trouble with the Ford AOD in a Town Car. I would keep the 5 speed manual and let your girlfriend drive it, leave the wife at home. Just kidding of course, but it sounds like more trouble than it's worth to change the tranny.

A 4L60 sounds great, Jerry.

So, from what I’m reading, if I do this, I’m going to have to weld in front side mounting pads for the car style engine mounts, remove the rear crossmember, and install a new crossmember at the rear of the transmission. Welding on my frame is where I’m going to draw the line, so it appears that this whole idea is for naught.

If powerglides were offered as an option on ‘50 trucks, how did they deal with the truck engine mount setup- you’ve either got to have one mount in front and two in the rear, or two in the front and one in the rear….. did the factory modify the truck frame for car style front mounts and creat a different rear crossmember??

Sounds like I need to stick with my T5…!

The powerglide was not offered in trucks until the 60s (1964, based on my reading).

Enough things were different by then that I don't think you can really leverage that setup.

You let your wife drive?
What is this world coming to?
Don't tell me. You let her vote, and wear shoes when she isn't in the kitchen too I'll bet.
(I sure hope that Miss Peggy doesn't see this post or I'll be is some hot water.)

Yeah, you are inviting all kinds of trouble right there…

Yep, Carl lives on the edge. Back on subject, Not really an option for a swap today, but in '54 a Hydramatic automatic transmission was an option. About 30 years ago one of my uncles had a nice original green 1954 3100 he'd picked up for a song and it was for sale when I saw it. That was in my foolish days and I didn't buy it. Don't recall the price but it was cheap and while the truck didn't look new it was in amazing shape. Dang it!

RonR

RonR, talking about regrets in the Mopar realm. The first one I tracked down and went to see was the year and model I wanted and went to see in Indy. Yes it had flaws but so do I. . But they did not make it inoperatorable. Passed it and now regret. Especialy since prices have gone up.

A few years ago, my buddy Jerry (Years of experience working on classic Chevy Cars/Trucks for a living) installed a Car powerglide in our buddy Dave's truck so that Dave's wife could drive the truck more. I took a bunch of pictures at the time. If I recall Jerry used car style mounts on the front of the transmission and moved the truck trans crossmember further back in the frame and modified it to support the rear of the transmission. He also reworked the car shift mechanism to make it look and work as though GM had installed it.
Here's the link to the pictures.. https://photos.app.goo.gl/y13hfZUUzpadFgML9
Also here is the info I got from Jerry at the time, also included with the pictures.
"Transmission is a 53-54 Powerglide it's desirable because it has a kickdown where the 50-52 doesn't. The shift collars is also 53-54 Car and the handle had to be modified to clear the steering wheel. The shaft that runs down the collar had to be shortened about an inch to fit the truck column. The shift levers and accelerator linkage also had to be modified a little. The truck cross member was used but modified to hold the rear transmission mount and side mounts had to be made to fit the front of the trans to the truck frame. Also needed the Powerglide trans cooler and lines."

Hopefully this give you another option for a more traditional trans swap.

Of not at some point I saw some info from GM from the 50's regarding retrofitting automatic transmissions, hand controls and power steering into late 40's and early 50's cars and trucks at the dealership to make them easier to Drive (Sell) to veterans coming back after the war that were amputees' so these kinds of swaps were done at the time.

~Mongo

I'm not knocking the 4L60, but you would need to change from 6V to 12V (see Tech Tips for how to) then buy a transmission controller (computer in a box) which requires you to link up with a laptop computer (or handheld device with APP) and make setup changes yourself (trial and error procedure) in the software provided. You also need a new radiator with transmission fluid cooler or a stand-alone cooler. At this point you have already broken the "originality ice" so you might as well replace the carburetor with fuel injection including electrical fuel pump and a gas tank with recycle connection. They make a box that controls both transmission and EFI. The original speedometer is mechanical so you would need to buy a mechanical to electrical converter. If you love computers and programming; this is the way to go. As is with all after-market electronic kits, they are subject to have unforeseen bugs are failures because the manufactures do not have the resources to stress test like GM, Ford, Mopar and other major automobile manufacturers.

A good rebuilt TH350 transmission, with adapter kit for a 261, does not require any electrical changes but the transmission final gear is 1:1 so unfortunately the is no OD. A rear axle gear change and taller tires will help but you don't have that wide range that 1st to 5th gears give you with the T5 BUT the wife is happier.

A compromise would be to buy a used modern truck, as a second truck, that has all options that you want, so your and wife are happy can be happy.

How about teaching the wife to use a clutch? Cheapest and easiest solution.

All right crew. This has gone waaaaay off topic. I removed some of the more egregious cruft and am locking this down for now.

Norcal Dave: if you want followup on this discussion, PM me and we can re-open it with a caveat that it needs to stay on target.