When I got my truck about a year ago it had a 1957ish 272 with a T-98 in it. There is nothing wrong with a T-98 generally mine how ever had worn out synchro's as I would assume most do.
I had already installed a 1972 dana 60 with 3.73 gears so am overdrive was not really needed but would not be annoying so....

I could have just rebuilt the T-98 but where is the fun in that?

I chose the NV4500 because it does not have an integral bellhousing, therfore it should be easier to install/adapt to the Y-block.

I will add pictures later but I have been running this transmission for about the months now with no problems.

The transmission is rated at around 15000 gvw max so it should be good behind y-blocks and bigger ford trucks.

 

__Sounds interesting , waiting for pictures now.____Welcome.____JIM

 

Alright, first some research history. There are several different versions of the NV4500 you can get there were ones used by Dodge and ones used by Chevy.

Some of the Chevy versions have a 10 spline shaft about 6.5" long

I think most of the Dodge ones have a 7.5" 10 spline shaft.

I think both are about 1.25

I am not sure if they came factory behind big diesel Dodges but you can get a 7.5" input shaft with 10 splines that is 1.375 in diameter and should technically slide right into the existing clutch.

So I found my tranny at a local pick-N-pull junkyard and got it for around $150. It was out of a chevy with 10 splines.

Here is the one I bought.

 

Here are some amazing measured drawings I made of both the original and the new tranny.







Now my measurements of the spigot that inserting into the bellhousing were off and they were actually exactly the same diameter, which this picture does not show exactly but here is what it looked like.




I was initially planning to weld bosses onto the bellhousing then drill and tap them so the transmission would bolt to the bellhousing in the normal orientation.... BUT then I had a stroke of genius!

 

Left with a "cliff hanger" with that last sentence . I'll be back.

 

Here is my brilliant plan!

I basically just marked out then drilled and tapped 4 holes into the face of the transmission. There was plenty of material to support the threads. I did not loctite them in or anything I just torqued them properly when I installed them.











Next from the dimensions you may notice that the pilot bushing and the sleeve for the throwout bearing needed to be a little larger in diameter. Because I have a lathe this was no problem.








They were both supposed to be press fit but one clearly was welded on because I was too lazy to start again from scratch.

 

Now going back to the detail drawings you can also see the splined section was not quite as long as on the T-98. This turned out to be the least of my problems .

Now on the original clutch and flywheel the clutch spring pack is offset and the clutch disk is offset away from the flywheel. The flywheel surface is flush almost all the way down to the bolt pattern area in the center.

GM being cheap and lazy made their clutch disc center on the friction material. now when I tried to mock it up it needed to have the flywheel clearenced to allow the spring pack to recess in. This would have taken paying someone else to do something so I had ANOTHER stroke of genius!

I would just install a spacer!!!

While looking for one I found these!














This is actually a friction pad for some aluminum flywheel, Fidanza 221101 from amazon about $50 now.

It was of course marked out and centered with precision! I centered it off the crankshaft spigot area and have not noticed any off balance-ness or shaking.

GENIUS!!!!!!

 

Couple of questions, but a clever adaptation!

Why the NV4500? I would guess a 3500 would be just fine for a Y-block even in hard use, and it's 1/2 the weight. 1st gear on the 4500 would seem to be about useless other than for parades?

Is the flywheel spacer plate just flat iron, or is it a purpose-made flywheel facing (like for aluminum flywheels)?

 

I choose the NV4500 because it is a truck transmission, the fist gear is a bull gear just like the T-98 was.

The NV3550 is used in Jeeps and small trucks, I think it is harder to adapt because of how it mounts to the existing bellhousing. Now it may be heavy enough for an F-100 or F250 but I wanted the 4500.


For aluminum flywheels. part number listed in bottom of last post.

 

Now that the easy things were out of the way I had to make a support for the clutch U shape thingy and the hand brake lever. The T-98 had a band brake on the back. You can get versions of the NV4500 with a drum brake on the back from the bigger trucks but that would cost more money. So I added a linkage on the side of the tranny for using brake cables that will go back to the Dana 60 when I get around to install them.













and there it is boys. Now you could also buy 1.375 input shaft from ebay for the dodge and make an adapter spacer to go in between the tranny and bellhousing. This way you would not have to machine anything maybe... Just make an adapter plate to bolt in between the two.

I also had to have the driveshaft shortened a bit...

 

Nice work. I am always envious of anyone with any machining skills and tools.


My version of machining uses a 4.5" angle grinder and a drill press.

 

Great information.

 

Thank you for the compliments.

I think it would be easy enough to do but a lathe or friend with a machine shop would probably be needed.

You could buy the larger 1-3/8" 10 spline input shaft assuming the gearbox you got did not come with it then make a spacer adapter that you would bolt to the bellhousing then bolt the transmission to it, the spacer would be about an inch thick piece of aluminum I think. Doing it this way it may be possible to do without removing the bellhousing unless you replace the clutch as well.

 

I'm assuming this is the T98 based on the larger pilot shaft diameter. Are these typical dimensions for the T98 or does yours have a larger input shaft? I've been researching a T98 to 5 speed swap but everything I've read thus far has shown the Ford T98 to have an 1 1/8" 10 spline input shaft.

Did you reuse your clutch disc and pressure plate or end up replacing them for the smaller input shaft size?

 

I too had read that the T98 had the small 1-1/8 but I can not be certain. I saw another one that certainly came off a 1954 F350 I think and it had the larger input shaft like mine. I am not certain what year they changed to the 1-1/8, maybe that was for F100s and the F250s and F350s got the 1-3/8?? You would have to have numberdummy or someone else with part numbers look it up.

Because mine did not have the 1-1/8" input I had to buy a new clutch disc and that is why I needed the spacer as well. I could have also taken the flywheel to a shop and perhaps had them grind out an area to clear the new clutch disc.

I used a new clutch disc but used the existing pressure plate. I also added that spacer to the flywheel which meant I needed spacers for the pressure plate or it would not disengage.