I have been looking into putting a Tremec 4050 behind a 390 FE in my 1973 F250 4x4. From what I've found it is a decent transmission that meets my criteria. It shares the input shaft length and spline count (6 1/2" long 10-spline) of the NP435, and is offered in a 2wd configuration (with a yoke out of the back) and an O/D gear. I've found an adapter kit that may work for the bellhousing from advance adapters although the website says its for the 300/302/351 bellhousings. From my understanding the bellhousing to case bolt spread is the same, I don't have both styles to compare. I also realize the TR4050 requires a hydraulic clutch setup, the crossmember would need to move, the transmission to t-case driveshaft would need the length adjusted, and would require a different pilot bearing. What has been done to make one of these work?
I am looking for a bit more information on the swap before I start. My truck has a divorced T-case (NP205) that I plan on keeping, and it currently has an NP435. I don't currently own a TR4050 but plan on buying one soon if the swap sounds doable enough.

Side note: when looking into these transmissions, I noticed that the ford configuration has a different 1st gear ratio.
Ford: 5.81
Dodge/GM: 6.16
Link for Adapter: : https://www.advanceadapters.com/dodge-nv4500-to-ford-v8-bhsg?srsltid=AfmBOooS4_-MSR0jDFjcD_dNAntX2wzoukNUi91-FDC0jHw43Pmphv-Kf3w
Link for Ford configuration: https://americanpowertrain.com/shop/...saAiAxEALw_wcB

 

I think quicktime offers a bell housing that will work.

The TR 4050 transmission on paper seems really really good!

If it wasn't for the approx. $5k in all-in cost (converting from auto) I would love to put one in my supercab.

 

A friend just did it to his 79 Bronco with 351.
Obviously not the same bell housing configuration, but the company he used was Modern Driveline.
Now in Idaho, I believe.

 

I did some looking into that QuickTime bell and I think it would put the input shaft too far from the back of the crank. The input is 6 1/2 long and the bell is 7” deep. I’ll try to contact them and see

 

That is a good looking option. I see adds for these in the $3,200 range.

https://americanpowertrain.com/shop/...8aAos2EALw_wcB

 

I considered doing this on my 76. The motor needed a lot so I ended up doing a full swap - TR4050 and 347 stroker.

You're correct that you'll need a hydraulic clutch, and I highly recommend Centerforce; it works/feels great and even the rubber pad looks stock.

 

Following up on this thread, after doing some more digging I’ve found a few different variations of this transmission. As mentioned before, the Dodge and GM configurations are identical internally. Ford has the different low ratio.

One thing I’ve noticed was certain websites only carry the GM and Dodge configuration. Just something to look out for. I have a while yet before I am ready to purchase the transmission and perform the swap.

I’ll keep the centerforce hydraulic setup in mind. For those who have done it, did you have to modify the transmission tunnel at all? How did you do the crossmember?

 

Why not just do a Gearvendor?

I put one on my '76 highboy and I love it. fits between the NP435 and the T case so no alterations were needed except a T case shifter mount and double joint coupler. now I have a 7 speed and it goes down the road at 60MPH turning 2,000.

 

Sorry to hijack- 440, what did you have to do for a T case mount with the gearvendor?

 

when you install the GV the rear housing on the NP435 has to come off and you lose your shifter mount. I just made an L bracket that bolts to the crossmember to reinstall it in the same location.

Since the GV goes between the trans and T case your speedometer and 4WD still work as before. I just mounted a small rocker switch on the shifter and that's about all there is to it. Tom Woods made me the coupler to connect up.

 

I’d like to keep it as simple as possible. Cost is another factor. With so much similar between the NP435 and the TR4050 I figured it may be better to just have a TR4050 because of the overdrive.

 

The GV can be installed in an easy day. that's simple. and the numbers I'm seeing for the transmission set up are considerably more expensive. so I don't see any savings and you have 5 gears not 7. just say'in.

 

To give another reason, I feel it would be pretty cool to do something different. And by simple I mean mechanically simple (Less moving parts). There is nothing wrong with going the gear vendor route, I just want to be a little different from the common option. My work may start being a TREMEC dealer soon so I may have some savings as well.

I would like to add, I am not set on anything yet. I have a long way to go before I get to that point so I will take your points into consideration.

 

I just like what works best. I'm too old to enjoy reinventing the wheel.

I have a couple Tremec TKX's in cars and they are one of their cheaper transmissions, still as much as the GV so don't get your hopes up.

The other thing is the Tremec has to have the input PERFECTLY squared with the Crank ask me how I know. that was fun. and then there's all the other crap that goes with a conversion like this.

But if you have the time, money and desire anything is possible so you can do it. good luck.

 

Would have to agree with 440 Sixpack....the GV will give you essentially the same OD ratio as the TR4050 and is overall cheaper and easier to install. On top of that you get more gears.

The TR4050 makes sense if a guy needs a new transmission in the first place...at that point the cost for a rebuilt stock trans and GV unit combined are greater than the 4050.