I went from a 3.89 rear end to a 3.25. It actually changed the feel of the car quite a lot, not only on the highway but running through the gears as well. Was the AMC tranny a Borg Warner?

I retained my 3.89 gears because of the stop and go on hills in my area. With the T-85 OD it runs nicely on the freeway between 65-75 mph cruising but it tops out at about 95 mph 

Does anyone know if the Amc tranny would mate uo to the y block bellhousing?

I had one of the overdrive toploaders installed behind an FE in a '57 for a while.  It replaced a wide-ratio 4 speed toploader.  In addition to the OD (about 0.80), the nice thing about that trans is the deeper 1st gear (3.29) compared to the wide ratio (2.78) transmissions.  I think the 3-speed transmissions have similar 1st gear ratios as the 4-speeds?

The car originally came with a 3-speed and 3.56 rear end.  To try to help highway behavior, we swapped to a 3.00 rear not long after we first installed the wide-ratio non-OD trans.  This definitely helped on the highway.  But, it also required careful clutch manipulation at launch to get a smooth start.  After we put in the OD toploader, launches were a LOT easier/less finicky.  Something of the best of both worlds for starts and highway cruise.

I've read a bit about the OD transmissions being "low performance".  After taking it apart, I wonder if people aren't confusing different "performance" aspects.  Well, that and potentially confusing the toploader ODs used in late 70's Granadas and trucks with later OD transmissions (SROD, etc) that were designed for lower HP applications. 

As far as the hardware is concerned, I believe, with the exception of the OD gear, everything is largely the same.  Input and output shafts are identical.  Nothing appears to have been tweaked (except the bulge in the case for the larger gear) or degraded knowing they were going into low HP applications.  If you put the OD trans in to replace a standard toploader because your engine twisted the previous transmission's internals into pretzels, you're probably going to see the same with the OD, too!  There does not appear to be any hardware differences that would make someone think the OD version wouldn't survive anything the non-OD version would. 

I do think there's an obvious performance hit from the larger spread between gears.  The OD toploader should be thought of as more like a 3 speed with overdrive rather than a conventional 4-speed.  The ratios on the OD would be something like 1st, 2nd and 4th on a conventional toploader.  Not terrible for "normal" driving.  But, you'd miss the performance help you'd usually get from non-OD 3rd gear.  In fact, this is why we went back to the wide ratio 4 speed.  Decided it was overall more fun to drive with the original 4 speed.  Seems we're backing our way into something like a TKO 5-speed to really get the best of ALL worlds!

I want to keep my shift on the column, but need the 80% (or so) high gear.

Put one of those in a 48 half ton behind a 66 390GT engine with a 4.11 posi.  Beat it hard, never had an issue.  As stated first gear is really down there, great for "normal" street but sucks for drags.

I found a Saginaw 3 speed with OD. Fully synchronized. Adapting it would be a chore but.....


https://www.ebay.com/itm/SAGINAW-3-SPEED-CAR-TRANSMISSION-2-85-BORG-WARNER-R10-OVERDRIVE-1-YEAR-WARRANTY/352925919715?hash=item522c0629e3:g:YGsAAOSwYpxeFmPX

For quite a few years Ford did offer a fully syncronized 3 speed manual transmission with overdrive. It was available in many Ford cars and light pickup trucks in the mid 60s into the 70s. Column shifted with a cable control knob under the dash. If you could find one of those transmissions, I am sure you could make your "3 on the tree" column linkage work.                                                                                                                                    Concerning the "Orion" 3 speed +overdrive sorta Toploader, the low performance designation is 2 fold, first off, the wide ratios are horrible for brisk acceleration, the RPM drops are quite steep, although for a cruiser type car, likely not much different than a straight 3 speed manual. But certainly a detriment for strong acceleration thru the gears. Also, the fact that the gears themselves are much different size wise, means that the torque capacity is less than say a 4 speed toploader. Again, for a non performance application, not likely a concern.                                                                   
Personally, after having installed several in various 302 cars, I think a 85-93 Mustang 5.0 T5 would be an excellent choice behind a Y block. Most have a low  3.35 1rst gear ratio, fairly evenly spaced ratios, plus a nice overdrive ratio. Bonus points for lightweight aluminum construction, easy shifting, and millions were built, & are fairly strong. Years ago I swapped out a C4 automatic for a junkyard T5 in my 78 Fairmont with a warmed over 302. I had 3.55 gears in the 8.8 rearend, and short 205/75R14 tires, on the freeway, the RPM was almost 3000 with the C4, with the T5 , dropped to just over 2100 RPM. Also at the dragstrip, the best with the C4 was 13.72 @101 MPH, with the 5 speed best was 12.80 @105 MPH. And the increase in driver fun was off the charts. Of course, you would have to have the floor shifter, and possibly either modify the stock bench seat, of install bucket seats to clear the shifter. Although if you have the bench seat all the way back, the shifter may clear the seat OK. On my Fairmont, I retained the factory bench seat, but if you moved the seat more than 2 spots foreward , the Hurst shifter would contact the seat. You can either buy an adapter to install a T5 to the Ford bellhousing, or Quicktime makes an scattershield style bellhousings specifically intended for a Y Block/T5 combination. Not sure if that route requires a later style starter or not.

QuoteI would like to change to a fully synchronized 3 speed manual trans. with electric overdrive (for road trips). What part# transmission would I be looking for and what year and body style would it come from? If anyone can supply this info I ,I thank you.

QuoteI ant to keep my shift on the column, but need the 80% (or so) high gear.

Looks like the conversation wandered a bit from your original question....   From what you describe, a good option would likely be the BW T-85 transmission.  With the exception of not having a synchronized 1st gear, it would seem to fit your requirements.  The OD ratio is roughly 0.7 in that transmission as well.

Here's an article from Hemmings on the transmission, vehicle applications and some notes on swap issues and things to look for : https://www.hemmings.com/stories/article/warner-t-85-t-89-three-speed-transmissions . 

Here's another from Hotrod that seems to do a good job of describing how the transmission (and OD cable) operates : https://www.hotrod.com/articles/1007sr-borg-warner-overdrive/ .  The "freewheeling-when-parked" feature unsettles me a bit.  But, probably like a lot of things once you know what to look for you can take steps to avoid the problem.  Obsessively setting the parking brake every time you stop seems like it would be a good habit to start!!

I would like to have one of those 60's transmissions that meteor mentioned. I will also check out those links that 81TTA mentioned. Thanks

The T85 three speed with OD will bolt right up and is a very strong transmission, but it is not fully synchronized. I have several of them and if I remember correctly, shifting momentarily to 2nd before putting it in first keeps it from grinding. The later 60's 3 speeds with OD would have the later wide bolt pattern, so getting it attached to a Y block is the complicating factor there.

Have never done it myself, but have heard of people installing 4 speeds (or the od toploader) using the 3 speed column and a separate kinda funky linkage rod under the seat for reverse. Knew a guy that installed one of the OD toploaders in a Mustang cuz he wanted OD, but he did not like the gear ratios and swapped it back out for a regular toploader. Think I got that transmission from him and it is on a shelf in my pole building still.

Those 4 speed toploader transmissions after 1964 are also the wide mount pattern, so that gets you back to the problem of it bolting to the narrow mount pattern bellhousing too. There were some transitional years (65?) that had both narrow and wide bolt patterns drilled. Later transmissions have the material there to drill the narrow pattern in them, but that is a job. 62-64 T10 four speeds are also the narrow mount pattern, but no OD there either.

So short of dealing with the mounting problem, you are stuck with a 1964 and older, or a 65 dual bolt pattern transmission to bolt right up to a Y block bellhousing, whether 3 or 4 speed. Retaining the column shift, it would seem the path of least resistance is either a T86 OD (standard duty) or T85 OD (heavy duty) transmission.  A T86 OD should be sufficient unless you drive very aggressively and can be picked up relatively cheap compared to a T85 OD.

Thanks for the info, that's very interesting I will not be driving very aggressive and the t86 or t85 would be ok. I can live without the first gear synchro. I havn't been doing much to my car lately, just staying at home. I did buy myself a pair of original aluminum valve covers that I had been wanting for a long time. Well thanks again and be safe. Barry

Just a minor note:
If you decide on a early 60's T85 as I did the shift arms have a bigger offset then the 57 trans. I think this was because the 60's cars had a wider frame. I simply swapped the shift arms from the 57 trans to the T85 and that allows the shift rods line up properly..

I just read BP57Custom earlier post about Amc T-85 Trans. I used one years ago in my Nailhead Buick powered Wagoneer.  It was from a 327 AMC Wagoneer.  Not OD, used Rancho adapter and Studebaker B.W. OD.  Bulletproof!  Anyhow to get to the point, the input shaft was about an inch longer, had to fab a spacer.