Trans Swap Wannabee

[Jonathan]

I am working on a 1950 Plymouth Deluxe and am trying to get better highway speeds. I have been looking for an overdrive unit with no luck. So, I searched the forum and found that some have swapped their transmission for a 5 speed manual Chev S10 T5 transmission. I have heard the first gear is really low. So I found a T5 Transmission from a 1988 Camaro / Firebird. Apparently the gears are more evenly spaced, which would be nice. However, a few questions:

 

1) Is the Transmission from the S10 and the Camaro / Firebird the same except the gear ratios?

 

2) The S10 has the gear shift 11 inches (so says a forum post) down from the opening of the transmission, and it is "ideally located." Is the shifter from the Camaro / Firebird similarly located? 

 

3) Is a 2.8 5 speed Camaro / Firebird transmission a failed option? I found one 5.0 5 speed manual & the junkyard is asking $1000 for it. (These transmissions are highly sought after for dragsters.) Alternatively, the same junkyard has a 2.8 5 speed manual for $400. I was thinking of going for the 2.8 as the weights of the Camaro / Firebird is similar to my Deluxe. Does this sound appropriate? 

 

4) Alternatively, are overdrive units for my 1950 Plymouth still available? I found one 1930s Ford R10, but do not think that would work for me.

 

Thanks. 

[Plymouthy Adams]

the gear ratio for the S10 smaller truck is by design geared in first and second to get you rolling and up to speed with the often equipped smaller anemic engines of the S10 when at load.  You will have the similar experience with the flathead if you get too tall in 1st and second via the close ratio gear sets...3-5 gear ratio is often the same or so close to the close ratio transmission you will effectively be the same with the truck wide ratio in the top 3 gears.  Many find the truck ratio effective just for this reason.  

[Roadtractor]

Where are you located? I search nationwide for deals on Mopar overdrives when I'm bored.

[andyd]

Whilst an original style Mopar overdrive will basically be as per what mother mopar installed they have the various solenoids & electrical bits which add to the possibility of problems........the S10 T5 gearbox is completely self contained with no electrical components and the S10 has the forward mounted gear lever due to its original use in a bench seat car which suits mopars...........the various gear raios can be an issue but my understanding is that they can be swapped between the various versions of the T5..........I imported a T5 yrs ago from California into Oz as we never had the S10 gearbox here.......andyd    

[Loren]

I have an S-10 T-5 in my 31 Model A Ford. The kit that was used was pretty awful but that's another matter. My main complaint is the choice of gear ratios used by GM in the S-10 T-5. They are terrible! The reason the S-10 T-5 is used is the location of the shifter and the fact that it has a mechanical speedometer drive. 

I know folks have problems finding B-W R-10 Overdrives but you have to be eagle eyed and you will find deals.

I bought one on eBay a week ago on a "Buy-it-now" for $250 plus $93 shipping from French Lake Auto Wrecking.

French Lake can be Googled and you can contact them directly if you'd like.

I have been a heavy advocate for the R-10 over the S-10 T-5 as most readers know. In fact I've been a pain in the neck about them and I apologize ahead of time for repeating myself endlessly.

What I like about the R-10:

Bolts right in, no adaptors required.

No cutting or welding.

You don't lose your E-brake

You can use the speedometer gear from your old transmission so there's no re-engineering there.

If you have the long transmission now, there are no issues. If you have the short wheelbase car you'll need to shorten the drive shaft and lengthen the E-brake cable with a coupler and a piece of rod which you have to thread ( or an All-Thread rod ).

Lastly there is the throttle switch and the relay. I have found alternatives to the very high priced reproductions. The wiring is easy and the diagrams are available on this site.

The top gear in an S-10 T-5 is a 28% overdrive while the top gear in the R-10 is 30% overdrive.

If you still have to have an S-10 T-5 I have one for sale.

[Roadtractor]

1 hour ago, andyd said:

Whilst an original style Mopar overdrive will basically be as per what mother mopar installed they have the various solenoids & electrical bits which add to the possibility of problems........the S10 T5 gearbox is completely self contained with no electrical components and the S10 has the forward mounted gear lever due to its original use in a bench seat car which suits mopars...........the various gear raios can be an issue but my understanding is that they can be swapped between the various versions of the T5..........I imported a T5 yrs ago from California into Oz as we never had the S10 gearbox here.......andyd    

There is the possibility of problems as with anything, I've logged close to 90k trouble free miles on mine that's configured as "mother Mopar" intended (plus a governor override toggle switch). But I also have a stack of spares and that knowledge probably convinces the old girl to keep working as intended.

[Bobb Horn]

Another option for a trans swap is the older Ford Ranger 5 speed, TKO, 1983 to 1988 I believe.    I installed one in my 38 Coupe several years ago, still does very good, easy install, no adapter needed or welding involved.    Also installed the Ranger rearend, 3.7,  as the stock rear had a lower gear ratio, and a Explorer driveshaft.

[keithb7]

Whats your crown and pinion gear ratio? What is your tire size? Do you live and drive in hilly or flat terrain? How much luggage and passengers are you carrying around?What is your desired top speed? Lastly, does your car use stock brakes and stock worm gear steering with king pins?

Edited October 15, 2022 by keithb7

[Jonathan]

19 hours ago, Roadtractor said:

Where are you located? I search nationwide for deals on Mopar overdrives when I'm bored.

I am located in Saskatoon, Saskatchewan. 

[Jonathan]

15 hours ago, Loren said:

I have an S-10 T-5 in my 31 Model A Ford. The kit that was used was pretty awful but that's another matter. My main complaint is the choice of gear ratios used by GM in the S-10 T-5. They are terrible! The reason the S-10 T-5 is used is the location of the shifter and the fact that it has a mechanical speedometer drive. 

I know folks have problems finding B-W R-10 Overdrives but you have to be eagle eyed and you will find deals.

I bought one on eBay a week ago on a "Buy-it-now" for $250 plus $93 shipping from French Lake Auto Wrecking.

French Lake can be Googled and you can contact them directly if you'd like.

I have been a heavy advocate for the R-10 over the S-10 T-5 as most readers know. In fact I've been a pain in the neck about them and I apologize ahead of time for repeating myself endlessly.

What I like about the R-10:

Bolts right in, no adaptors required.

No cutting or welding.

You don't lose your E-brake

You can use the speedometer gear from your old transmission so there's no re-engineering there.

If you have the long transmission now, there are no issues. If you have the short wheelbase car you'll need to shorten the drive shaft and lengthen the E-brake cable with a coupler and a piece of rod which you have to thread ( or an All-Thread rod ).

Lastly there is the throttle switch and the relay. I have found alternatives to the very high priced reproductions. The wiring is easy and the diagrams are available on this site.

The top gear in an S-10 T-5 is a 28% overdrive while the top gear in the R-10 is 30% overdrive.

If you still have to have an S-10 T-5 I have one for sale.

Thank you very much for the information! I will contact them and see if I can get some traction on the R-10. 

 

I do not really "need to have" the S-10, per se, but I do need to lower my rpms. 

[Jonathan]

13 hours ago, Bobb Horn said:

Another option for a trans swap is the older Ford Ranger 5 speed, TKO, 1983 to 1988 I believe.    I installed one in my 38 Coupe several years ago, still does very good, easy install, no adapter needed or welding involved.    Also installed the Ranger rearend, 3.7,  as the stock rear had a lower gear ratio, and a Explorer driveshaft.

Ok, that is another option I was not aware of. I will research Ford Ranger 5 speed. Were there any other forum posts on this option? It would be great if the bolt pattern would be the same.  

[Jonathan]

13 hours ago, keithb7 said:

Whats your crown and pinion gear ratio? What is your tire size? Do you live and drive in hilly or flat terrain? How much luggage and passengers are you carrying around?What is your desired top speed? Lastly, does your car use stock brakes and stock worm gear steering with king pins?

I swapped my original rear end to a 1994 Ford Explorer. I am guessing my original rear end was 3.75, my new rear end is 3.27. 

 

My tire size is 195/65 R 15. They are a 24" diameter tire. 

 

My terrain is generally flat. 

 

I would not be carrying that much luggage, but I could be carrying a full load of passengers. It is a 5 seater car. 

 

I do not really have a top speed I am looking for, but I am looking for a desired RPM at highway speeds. I believe a good highway engine RPM (based on the power curve of my 251 engine) would be between 2000-2500 RPM. Engine seems to have the most torque between 1500-2500 rpm, see attached picture. Please correct me if I am wrong on this and my highway RPM expectations. Here is my math:

 

Where I am now:

1) 195/65 R 15 tires, 3.27 rear end, original transmission, (1:1 top gear) at 62.5 MPH (100 KMPH) is 2860 RPM

2) 195 65 R 15 tires, 3.27 rear end, original transmission (1:1 top gear) at 68.5 MPH (110 KMPH) is 3130 RPM

 

Change Tires Only:

3) 205/75 R 15 tires, 3.27 rear end, original transmission, (1:1 top gear) at 62.5 MPH (100 KMPH) is 2550 RPM

4) 205/75 R 15 tires, 3.27 rear end, original transmission (1:1 top gear) at 68.5 MPH (110 KMPH) is 2790 RPM

 

Change Transmission Only:

5) 195/65 R 15 tires, 3.27 rear end, O/D transmission, (.75ish top gear) at 62.5 MPH (100 KMPH) is 2150 RPM

6) 195 65 R 15 tires, 3.27 rear end, O/D transmission, (.75ish top gear) at 68.5 MPH (110 KMPH) is 2350 RPM

 

 

Change Tires and Transmission (I do not know if I could/should do this, it might be too much for the engine):

7) 205/75 R 15 tires, 3.27 rear end, O/D transmission, (.75ish top gear) at 62.5 MPH (100 KMPH) is 1900 RPM

? 205/75 R 15 tires, 3.27 rear end, O/D transmission, (.75ish top gear) at 68.5 MPH (110 KMPH) is 2090 RPM

 

Because I changed the rear axle to a Ford Explorer, it has the Ford Explore drum brakes in the rear. The front brakes are original and the steer is original.

 

 

Edited October 15, 2022 by Jonathan

[Sniper]

I put together a spreadsheet looking at some of the more common OD swaps. 

 

 

[Bob Riding]

On 10/14/2022 at 6:42 AM, Jonathan said:

I am working on a 1950 Plymouth Deluxe and am trying to get better highway speeds. I have been looking for an overdrive unit with no luck. So, I searched the forum and found that some have swapped their transmission for a 5 speed manual Chev S10 T5 transmission. I have heard the first gear is really low. So I found a T5 Transmission from a 1988 Camaro / Firebird. Apparently the gears are more evenly spaced, which would be nice. However, a few questions:

 

1) Is the Transmission from the S10 and the Camaro / Firebird the same except the gear ratios?

 

2) The S10 has the gear shift 11 inches (so says a forum post) down from the opening of the transmission, and it is "ideally located." Is the shifter from the Camaro / Firebird similarly located? 

 

3) Is a 2.8 5 speed Camaro / Firebird transmission a failed option? I found one 5.0 5 speed manual & the junkyard is asking $1000 for it. (These transmissions are highly sought after for dragsters.) Alternatively, the same junkyard has a 2.8 5 speed manual for $400. I was thinking of going for the 2.8 as the weights of the Camaro / Firebird is similar to my Deluxe. Does this sound appropriate? 

 

4) Alternatively, are overdrive units for my 1950 Plymouth still available? I found one 1930s Ford R10, but do not think that would work for me.

 

Thanks. 

I just PM'd you.

 

[Jonathan]

I have a possibility of an R7 overdrive/ 3spd transmission from a 1940 Chrysler. Is there a difference between the R7 and the R10? Will an R7 from a 1940 Chrysler simply bolt on my 1950 Plymouth Deluxe without any modifications? Thanks.

[Loren]

It is safe to say the R-7 is more rare than the R-10.

It certainly is more antique than the R-10.

The first Mopar R-10 being May of 1952.

I am sure it might bolt in but you might want to stay with the R-10 because of the volume of parts still around.

I mean that is the safe recommendation.

[Roadtractor]

The '40 chrysler trans might fit, the R-7s had at least two? different transmission cases from what ive seen. The earlier ones had the transmission "tower" bolt to the bellhousing, around/during 1940 they switched to the side shift transmission case design and the tower no longer bolted to the bell. If it's the later trans case design then it should bolt into your 50. The R-7 is a little more difficult to find parts for but Studebaker used them as well which opens up the availability a tiny bit for od parts. They're a good unit and if the price is right I'd snap it up. If you were closer to Iowa I'd consider trading a R-10 for it as I don't have a R-7 side shift case in my collection yet.

[Bob Riding]

Here is the OD @Jonathan is referring to. Looks like a side shift to me. Comments?

[Sniper]

That is a side shifter

[Roadtractor]

Pretty cool! That is the unusual 1940+ case with a R-7 overdrive. It should bolt in to any 1940-55 standard wheelbase Plymouth. Also, it has the later style shifter arm on it so it has probably already been in a 1946+ car. 

Edited October 18, 2022 by Roadtractor

[Bob Riding]

2 hours ago, Roadtractor said:

Pretty cool! That is the unusual 1940+ case with a R-7 overdrive. It should bolt in to any 1940-55 standard wheelbase Plymouth. Also, it has the later style shifter arm on it so it has probably already been in a 1946+ car. 

Good to know, thanks!

[9 foot box]

[Bobb Horn]

On 10/15/2022 at 10:32 AM, Jonathan said:

Ok, that is another option I was not aware of. I will research Ford Ranger 5 speed. Were there any other forum posts on this option? It would be great if the bolt pattern would be the same.  

I started a thread years ago of "5speed, not T5", when I started my TKO Ranger transmission install.    I used a 37 or 38 bellhouse, Ranger clutch.   the near 5inch bell hole was enlarged a small amount to fit the TKO.   the 3.7 Ranger rear is a little to low, but does great in my steep driveway. 3.9 was too low, 3.5 Jeep may be the sweet spot.   top end ratio is great with the 3.73.       this photo the bell attached to my 56 engine for test fit.

[Jonathan]

On 10/19/2022 at 10:22 PM, 9 foot box said:

Is this info for a 251 flathead 6 engine, with a 3.73 rear end?

[9 foot box]

   The calculator chart doesn’t care what engine you use. Your car originally had 6.70x15 tires, that simply equates to a 28” tire. I run 215/75r15 Hankook tires on stock 4.50” wide wheels, with a 3.9 gear ratio. The speedometer reads correct in a school zone radar indicator. I’ve had it up to 80 mph. You initially said you had 195/65r15 tires and a 3.27 gear ratio. ? With 28” tires and 3.73 gear ratio, you could be driving 70 mph at about 3130 rpm.  Rick D.