Manual to Auto in a 63
 

After a year off the road for engine restoration and Muncie rebuild, I realized this fall that a huge part of the reason I don’t drive my 63 often is the manual transmission in Dallas traffic.

I have had the car for almost 10 years—there are a few things left but everything else has been R&R. There are a multitude of auto to manual threads as well as PG to 700r4 or 200r4 threads but only a few manual to auto. I think I have a good list of everything I need (please let me know if I have missed something).

Flex Plate
Transmission
Torque Converter
Auto Shifter
Speedo Cable
Pedal Assembly
Kick Down Linkage
Auto Console
Neutral Safety Switch
Drive Shaft
Trans Cooler
Trans Mount

I do have a few questions:
Are the 63-64 consoles the same for manual and auto—just need to change the plate?
Kick down linkage—I need to research this but is there a way to use my existing carter AFB?
NSS—I have a new dash wiring harness which if I recall was specific to manual and I assume no wiring for the NSS. Thoughts?
Pedal Asym—do I just need the bigger brake pedal or complete box?
Drive shaft--shorter/longer/same length?
Looks like trans cooler just bolts to existing radiator—could use aftermarket?

I have saved the worst for last: I am considering a TH350 for (a) cost (b) ease of installation—WILL NOT cut or modify my cross member and (c) something that is easily reversed for the next owner. I never get over 50-60 mph and never take it on the highway—at least not for extended periods. I know everyone will say go with the OD--and I have not ruled that out but the questions above I believe are independent of which transmission.

For those of you that have done this swap or the swap from AUTO to Manual, are there any other differences or things I may encounter?

what trans to use
 

I had a pg in my 65 sb replaced it with a turbo 350.every thing worked no need to change drive shaft.only had to buy a kit for t350 shift position selector.i love it

If you are thinking you might go to Holley EFI Fuel Injection someday. I would get either a 4L60E or 4L65E automatic transmission with overdrive.

Lets assume you are not considering a powerglide.

The simplest, easiest, cheapest way to go is a TH350. Bolts right in, no drive shaft length changes, and fairly cheap, all things considered.

The next simplest, cheapest, easiest was to go is a 2004R. Bolts in with very little mods, no drive shaft length changes, but can get a bit expensive.

For your intended use, the TH350 is clearly the right answer.

Frankie--are you asking about hole in core support for coolant lines? I would have to look but I dont think so. I thought the hole on the side was for FI?

I think the TH350 is probably best for me. I can start putting pieces together. Any thoughts on my remaining questions?

Are the 63-64 consoles the same for manual and auto—just need to change the plate?
Kick down linkage—I need to research this but is there a way to use my existing carter AFB?
NSS—I have a new dash wiring harness which if I recall was specific to manual and I assume no wiring for the NSS. Thoughts?
Pedal Asym—do I just need the bigger brake pedal or complete box?
Looks like trans cooler just bolts to existing radiator—could use aftermarket?

Console trim plate looks like it will need to be changed (console is fine). Also the retainers under the console trim plate will need to be changed.

I am fairly certain that your existing carb can be used, but you will need the lever with the hole in it to attach the kickdown linkage. Show us a picture of your throttle linkage.

The Neutral Safety Switch may need to be wired separately if the wiring harness does not account for it. It is not that hard to do.

You can remove the existing brake and clutch pedals, and install an automatic pedal. The pedal box is fine.

I would HIGHLY recommend an aftermarket cooler regardless of your transmission. If you existing transmission has provisions for trans cooler lines, then use them IN ADDITION to an aftermarket trans cooler. Heat is an auto transmission's worst enemy.

I do not recall if the driveshaft yoke will need to be replaced, but that is also an easy change.

This is actually a pretty easy swap. The biggest issue, as I recall, is getting the TH350 in the car. It is a bit tight sliding the TH350 back and over the cross member, but it can be done, and has been done many times.

One possible suggestion is modifying your cross member to make it removable, but that is sort of a permanent mod.

Keep us posted.

Thanks everyone. I am going to start gathering parts. I'll have to do some investigating on my wiring harness. I have replaced both the dash and engine bay with lectric limited so if it was supposed to be there, it is.

I told my older die hard 'cheby' guy about my plans and he rolled his eyes and said why.

Interesting reason to swap. Original automatic transmission for 1963 was power glide. Power glide is only 2sp but has reputation for being stronger than TH350. I would think either would allow you to drive as you plan to. I guess I would compare total cost for each and use the one with the steepest first gearing which should be the 2.52 in the TH350 and allow higher freeway gears (numerically lower). Plenty of C3 corvettes came with the TH350 and make good donors for your parts as I see plenty of C3 part outs on Craigslist - not horded like C2's.

I would install a trans cooler with any automatic transmission as heat is the worst enemy of any automatic transmission.

Good luck.

Hi TX63Conv:

Just thought I'd pipe in because I just came across your post about swapping in a TH-350 in your car. Although my situation was a bit different, I thought you might like to hear my experience. I have a '67 coupe which came originally with a 2-speed Powerglide automatic. It ran well enough, but I wanted more responsiveness off the line and more flexibility while driving on the hilly parts of town. The PG was okay, but its rather lazy 1.76 first gear ratio coupled with the fact my car has a 3.08 rear end meant rather relaxed acceleration overall. At first I seriously considered swapping in a 200-R4 overdrive transmission. In the end, I opted for the TH-350 instead. Going this route was a lot less expensive, and required fewer modifications to the car making it more of a bolt-in operation. Oh, there were some things that had to be fiddled with to get everything working perfectly, but nothing too difficult. Also, the swap is almost completely stock-looking. Anyhow, in your case you'll be going from a 4-speed manual to an auto, so your considerations will be a bit different (pedal box, etc.). Despite that, I think you'll be very satisfied with the swapping in a TH-350. The combo of having a 3-speed auto, with a low 2.52 gear and an intermediate 1.52 gear really transformed the performance of my car. It now has much stronger pull off the line, has a second gear for passing and hill climbing, and all this works almost as if GM intended it to be so. Here's what I wrote in another thread about my experience with the TH-350:

As mentioned, others have been successful in swapping the Powerglide for a 700-4R, or a THM-350. I chose the latter and am very happy with the results. The THM-350 (otherwise known as the Turbo 350) was introduced in 1969 as GM's replacement for the Powerglide, and its size and chassis mounting is almost identical. It was derived from the legendary THM-400 introduced in 1965 for GM's full-size and high performance vehicles. The Turbo 350 is a medium duty 3-speed transmission, excellently suited to intermediate sized cars. The THM-350 does not have overdrive, nor torque converter lockup (except for the THM-350C which was used in 1980-81 - you should avoid that one!). In my case, lockup is no loss, and O/D isn't critical either, as I drive my '67 coupe only about 1,200 miles a year. My car has a 3.08 rear, so cruising at 70mph has the motor turning at a relatively calm 2,700rpm. The THM-350 is much stronger in stock form that any 200-4R (except for the noted Buick GN/ Chevy SS versions) and can be built to HD specs by any competent builder in your town. They are proven, and reliable. Cores are dirt cheap.

So here's what I did. I bought a THM350 core for $150 on Craigslist, had it rebuilt with HD parts and a manual control shift kit for another $700. Installation did NOT require a custom rear transmission mount as the THM-350 bolts right up to the Powerglide rear mount. The trans cooler lines bolted right up. The installer was able to use the stock steel tube dipstick (the 200-4R must use a flex type dipstick which does not look stock). The engine of my car (a 327-300hp) did not need to be moved. The right head pipe did have to come out, but that wasn't any trouble. I re-used the THM-350 vacuum modulator steel line and hose from the core - easy! I got a Lokar downshift bracket and cable kit (cheap). The exhaust did not need to be modified.

The whole swap cost less than $2,000 and it transformed the character of the car! It is now much more flexible for in-town and driving in hilly country, having a 2nd gear. Low gear is 2:52, which means I can fry the tires off the line if I want to get a bit frisky. All my needs are satisfied in a swap that was simpler (i.e. no rear mount fabrication, no finickly TV cable, no lockup electrics, no O/D control electrics) and cheaper when compared to using a 200-4R. Of course your needs may vary, so if O/D is a must for you, then the 200-4R would be the way to go.

Several forum members have successfully swapped out their Powerglides for 200-4R's. Search this forum for the terms "Powerglide swap", and "200-4R" or "Automatic". You'll learn a lot, and be better placed to make the right swap decision for your car and driving needs.

Hope this helps,
Alex

There is a large hold for the F/I air cleaner but a smaller oval hole near the V/R for PG coolant line later in 63. its less than the size of a dollar bill...


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