Transmission advice needed

[BowBronco]

Hi all, in the middle of a ‘73 Bronco restoration with my dad. Finished going thru 351w. Now looking for a transmission. Have a 3 speed manual to a Dana 20 T case. Want to convert to an automatic. What is the easiest swap here with little to no fabrication? C4, C6, 700r4? And where would be the best place to look? Been scouring marketplace to no avail. Any advice greatly appreciated. Thanks for your help Bronco brethren

 

[Gitkrunk]

interested to know as well

 

[bmc69]

An original Bronc factory C-4 is always the easiest route to take. Small-bell C-6s are not easy to find and are a tight squeeze and don't mate directly to D20. I did one very expensive 700R4 conversion...never again. The 4R70 or AOD Ford OD transmissions find themselves in many EBs. Adapters are available from Advance Adapters for most of these swaps; only the factory C-4 swap would use all original EB hardware.

 

[pcf_mark]

I can share what I did I think it also applies to a 351 but I have a 302.

Installed a used C4: plus side -fits right in, everything lines up downside - it only lasted a few months before total rebuild needed, was very expensive and difficult to find
C4 parts 2: rebuild parts are cheap but not easy to get anymore. I rebuilt it and it was fine but it is really no better than the 3 speed manual I took out in terms if driving experience.

Switched to a 4R70W out of an Explorer: plus side it was dirt cheap at $150, last forever, lower 1st gear and overdrive 4th. Downside - needed a NP205 transfer case ($150) and transmission controller ($350-$500) plus a new trans crossmember (I made my own) and updated driveshafts.

If you plan to drive it I would spend the money on the 4R70W upgrade I was really sorry I spent so much on the C4 to buy it and then rebuild to have it be disappointing.

 

[jamesroney]

I can share what I did I think it also applies to a 351 but I have a 302.

Installed a used C4: plus side -fits right in, everything lines up downside - it only lasted a few months before total rebuild needed, was very expensive and difficult to find
C4 parts 2: rebuild parts are cheap but not easy to get anymore. I rebuilt it and it was fine but it is really no better than the 3 speed manual I took out in terms if driving experience.

Switched to a 4R70W out of an Explorer: plus side it was dirt cheap at $150, last forever, lower 1st gear and overdrive 4th. Downside - needed a NP205 transfer case ($150) and transmission controller ($350-$500) plus a new trans crossmember (I made my own) and updated driveshafts.

If you plan to drive it I would spend the money on the 4R70W upgrade I was really sorry I spent so much on the C4 to buy it and then rebuild to have it be disappointing.

How long ago? The last Driver drop NP205 I sold last year went for $800. I see them now for over $1000. I Don't know if they are selling. Very popular in Jeep, Chevy, Dodge, and Ford conversions. Pretty sure the last one was built in 1979. So that's 43 years ago?

...I haven't seen a $150 NP205 for a Ford in a while. I did see a shifter for one for $150 tho.

 

[thegreatjustino]

Early Bronco Transmission Guide - Automatic Options

Tech article by Jon Hanna (Admin) This is the second article in a two part series on popular transmission swaps into your early Bronco. The first article focused on several manual choices for those who like to row their own gears. This second...

classicbroncos.com

4R70W 4 speed automatic with overdrive

Tech article by Tim Bowsher (Broncobowsher) Selecting a new transmission. It started with when I got the latest Bronco. I didn't want the old 3 speed anymore. I have heard about the NP435, so I got one. I ran along happily with 33's, 4.10's...

classicbroncos.com

 

[pinky]

I don't know what your time frame is but I have a c-4 in my bronco I will be selling . I just ordered an atlas for my 71. They said 19 weeks.

 

[pinky]

I guess it also matters where you are.

 

[jba6555]

I guess it also matters where you are.

where are you pinky?

 

[pcf_mark]

How long ago? The last Driver drop NP205 I sold last year went for $800. I see them now for over $1000. I Don't know if they are selling. Very popular in Jeep, Chevy, Dodge, and Ford conversions. Pretty sure the last one was built in 1979. So that's 43 years ago?

...I haven't seen a $150 NP205 for a Ford in a while. I did see a shifter for one for $150 tho.

This was about 3 years ago. It took a while to even find one but it was $150 and generally that price range.

 

[Jdgephar]

I have a small block two wheel drive C6 I took out of an F150 I'm willing to get rid of. It was a running, driving truck I took it out of. Probably 50k miles since it was rebuilt. I used the 351 it was attached to and dropped it right into my Bronco.

Sent from my SM-G981U using Tapatalk

 

[pinky]

Coeur d alene Id

 

[fordguy]

Hi all, in the middle of a ‘73 Bronco restoration with my dad. Finished going thru 351w. Now looking for a transmission. Have a 3 speed manual to a Dana 20 T case. Want to convert to an automatic. What is the easiest swap here with little to no fabrication? C4, C6, 700r4? And where would be the best place to look? Been scouring marketplace to no avail. Any advice greatly appreciated. Thanks for your help Bronco brethren

C-4 is a great trans, viper wolf usually knows good parts sources. Only use the pan fill C4 that came in the bronco. C6 is not necessary. Northeast (Nick) should have any small parts you need if you don’t get a complete setup. Kurt Strecher sells really nice C4s but they are not cheap. Be patient you can find a C4.

 

[Broncobowsher]

The C4 will give the vintage driving style like that of the stock 3-speed. The transmission may not be happy if you are running too tall of a tire for the gearing in the axles. You will really want 4.11s with 33s, more gear with taller. 3.50 gears will work if you don't go over stock sized tires.

Everything else will require some degree of fabrication and aftermarket adaptors, often with a required transmission rebuild to install the adaptor parts. In most cases you will be looking at an overdrive transmission which will need even deeper axle gears to drive good.

 

[Crazylilgreenmen]

I can share what I did I think it also applies to a 351 but I have a 302.

Installed a used C4: plus side -fits right in, everything lines up downside - it only lasted a few months before total rebuild needed, was very expensive and difficult to find
C4 parts 2: rebuild parts are cheap but not easy to get anymore. I rebuilt it and it was fine but it is really no better than the 3 speed manual I took out in terms if driving experience.

Switched to a 4R70W out of an Explorer: plus side it was dirt cheap at $150, last forever, lower 1st gear and overdrive 4th. Downside - needed a NP205 transfer case ($150) and transmission controller ($350-$500) plus a new trans crossmember (I made my own) and updated driveshafts.

If you plan to drive it I would spend the money on the 4R70W upgrade I was really sorry I spent so much on the C4 to buy it and then rebuild to have it be disappointing.

Will the 4R70 fit without a body lift?

 

[Broncobowsher]

Will the 4R70 fit without a body lift?

It is possible. Many have done it.

 

[pcf_mark]

I have a 4R70W w/o body lift and an NP205.

 

[Crazylilgreenmen]

I have a 4R70W w/o body lift and an NP205.

It is possible. Many have done it.

Thanks guys!