1961 - 1966 F-100 & Larger F-Series Trucks Discuss the Slick Sixties Ford Truck

NP 435 4spd transmission swap options to 5spd

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Old 02-01-2017, 02:25 PM
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NP 435 4spd transmission swap options to 5spd

I would like to swap in a 5 spd tranny to replace my existing 4spd NP 435. 1965 F100. The truck has the dana 60 rear, and 352 motor. I am hoping, obviously, that there is an option that would be a relatively straightforward swap. Thanks in advance!
 
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Old 02-01-2017, 02:56 PM
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It is hard to beat the NV4500. Here's a sample write-up by CeetWarrior. I also know SuperSabre went this route.

https://www.ford-trucks.com/forums/3...390-roars.html

.
 
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Old 02-01-2017, 03:00 PM
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My recommendation and personal plan is to swap in an NV4500 from a dodge 2WD GAS (not diesel) truck with the 1 1/4" 10 spline input shaft. If you can find one prior to '97 (or maybe '98) that has the mechanical speedo drive it will be a bit simpler bolt on.

There are several options for making this work. You can use any internally balanced 390 or 460 flywheel (176 tooth, 180 tooth 184 tooth all the same diameter). I'm using an aftermarket steel flywheel that has the late 460 pressure plate bolt pattern so I can use a late 80s to mid 90s F250 7.5 liter 12" clutch disc with the 10 spline 1 1/4" diameter 10 spline hub that will mate directly with the NV4500 input shaft. You could use a Dodge 11.5 disc with the 390s long style PP, but expect to do some grinding on the disc hub. If you don't want to swap out the flywheel, Tom's Bronco Parts sells an 11" disc with the 1 1/4" 10 spline hub that will work with the stock 352 PP. I just feel if you've gone this far don't cheap out now.

You will need an adapter from Advanced Adapters to go between the trans and the bell housing. I don't know the part number off hand, but you can search this forum or google "NV4500 adapter". It is the same one that works for a 5.0 liter in a Bronco. You can get them directly from Advanced Adapters or Summit Racing or Tom's Bronco parts among others around $250 last I checked.

To make the NV4500 speedo drive work you will need a Speedo gear pinion support from any late 60s to early 80s Torqueflight trans. You will also need a Dodge speedo gear. For 29" diam tires (235/75/15) and a 3.25 axle gear, you need the 31 tooth speedo gear, 3.50 axle gears require 33 teeth, 3.70 axle gears; 35 teeth. For 30" tires subtract one tooth. Edited to correct the tooth count

You will also need a longer cable. There are conversion cables available for a TH400 that are about 12" longer than stock NP435 cables. I haven't tried it yet but that's my plan.

Later NV4500s used an electronic output. That would work with a Dakota Digital gauge cluster or you can get a converter that will turn the electrical signal into a mechanical output.

I believe the diesel NV4500 can also be used. It has a larger 1 3/8 10 spline input shaft, but that's the same as the Boss 429 and 428CJ, so you can still get a disc that will slide right on... at least theoretically. I don't know anyone who's done this, and the 1 1/4 shaft is plenty big enough.

You will need a larger 410 series DS yoke that mates with the output shaft and will have to have a custom drive shaft made to mate with it.

You will need to fabricate a new trans mount. A member here was able to do that by simply flipping the stock xmember upside down along with a little cutting and welding.

I'm still gathering parts so I can't tell you much more than what I've researched, but I'll detail the install when I get to it.
 

Last edited by 66v8baby; 02-04-2017 at 08:55 AM. Reason: Corrected the tooth count
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Old 02-01-2017, 03:54 PM
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Excllent info, thanks folks. I did find a bunch of info on this in the forum, sorry for the repeat question.
 
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Old 02-01-2017, 07:15 PM
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The ranger overdrive splitter might be an option for you too.
 
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Old 02-01-2017, 09:30 PM
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If money were no object, I'd get a gear vender. But since money does matter, I would ask what is your goal? If all you want is less rpms on the freeway and you won't be towing heavy then keep the NP435 and change your rear axle ratio. The only real benefit to the NV4500 is its synchronized 1st gear. The NP435 actually has a wider ratio than the NV4500. Keeping the NP435 and changing axle ratios can get you to lower rpms cheaper than swapping trannies.
 
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Old 02-02-2017, 09:58 AM
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Originally Posted by '65Ford
The only real benefit to the NV4500 is its synchronized 1st gear. The NP435 actually has a wider ratio than the NV4500.
Synchronized reverse isn't a benefit? Closer gear ratios? Wider overall ratio? All these are benefits owned by the NV4500.

The NP 435 does NOT have a wider overall ratio than the NV. Overall on the NP435 is 6.69:1. Overall on the NV4500 is 7.68:1.

As for the gear vendor, unless you have a real hoss of an engine, the Ranger Torque Splitter gives you the same thing for 1/2 (or less) the cost.
 
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Old 02-02-2017, 10:24 AM
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Originally Posted by 1972RedNeck
Synchronized reverse isn't a benefit? Closer gear ratios? Wider overall ratio? All these are benefits owned by the NV4500.

The NP 435 does NOT have a wider overall ratio than the NV. Overall on the NP435 is 6.69:1. Overall on the NV4500 is 7.68:1.

As for the gear vendor, unless you have a real hoss of an engine, the Ranger Torque Splitter gives you the same thing for 1/2 (or less) the cost.
- I can't imagine ever needing a synchronized reverse... especially in a 1960's pickup. I always stop before shifting into reverse.
- Closer gear ratios are good if towing... but I said "if you won't be heavy towing". With a 352 and no towing, 3 forward speeds do fine.
- The widest ratio I've seen for the NV4500 (GM version) is 6.34 in 1st and 0.74 in 5th. That's calculates out to the same width as a NP435 with its 6.67 1st and 1.00 4th.
- Ranger Torques Splitter's main benefit is its lower cost. It's not as strong as a gear vender and you have to cut the front snout off your tranny. Neither may be a concern for some people. Again, if money's no object I'd get the gear vendor but since money usually is important I suggested the most economical route of swapping rear axle ratios.

Here's some info from a company that sells and rebuilds both trannies.
The Novak Guide to the NV4500 Transmission
 
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Old 02-02-2017, 11:22 AM
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As someone who has actually done the NV4500 swap,with thanks to Ceetwarrior, I can say that I am very pleased with it. I do occasional towing, as well as carting things around in my '66 longbed F100. What nobody has mentioned is the modern truck shift quality of the thing which is so superior to the agricultural nature of the NP435. With the NV4500 you get all of the good things that the 435 has, including the granny 1st gear that almost never gets used, plus the overdrive which knocks down the revs and noise. With 3.50 gears, I can go into 5th gear around 45 - 50 mph. My engine is a "built" 390 with a low rpm high torque cam. The only issue I would have with doing the swap these days is that some of the mechanical speedo parts that you have to source from Dodge are getting hard to find. Pictures of some of the swap are located in my album. I would be happy to provide more info to anyone who wants it.
 
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Old 02-02-2017, 12:14 PM
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Originally Posted by '65Ford
- The widest ratio I've seen for the NV4500 (GM version) is 6.34 in 1st and 0.74 in 5th. That's calculates out to the same width as a NP435 with its 6.67 1st and 1.00 4th.
The Dodge NV4500 that would have to be used for this swap has a 5.61:1 first gear ratio and a .73:1 overdrive.

5.61/.73=7.68:1 overall gear ratio

For the NP435,

6.69/1=6.69:1 overall gear ratio
 
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Old 02-02-2017, 01:54 PM
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Originally Posted by 1972RedNeck
The Dodge NV4500 that would have to be used for this swap has a 5.61:1 first gear ratio and a .73:1 overdrive.

5.61/.73=7.68:1 overall gear ratio

For the NP435,

6.69/1=6.69:1 overall gear ratio
Yeah, you're right. I must have "fat fingered" the calculator.

Still, I would be asking myself what my goals were with the truck to decide if I wanted to swap ring/pinion vs sourcing a decent NV4500, adaptor, yoke, modify the driveshaft, and modify the tranny mount... especially if I know my NP435 is good.

I'm biased since I have 3 NP435's and no known good NV4500. (I've found rebuilt ones for almost $2,000 online).
I like SuperSabre's point about the smoother shifting. Maybe the OP has a buddy with an NV4500 to compare shifting. My NP435's shift okay, though it's a long way moving from 1st into 2nd and then 2nd into 3rd.
 
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Old 02-02-2017, 02:25 PM
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Originally Posted by SuperSabre
As someone who has actually done the NV4500 swap,with thanks to Ceetwarrior, I can say that I am very pleased with it... I would be happy to provide more info to anyone who wants it.


I will take you up on that offer. I have this speedometer gear pinion support pictured. Do I need the long auto trans style or short (Jeep style) speedometer pinion gear? It looks like the short one would work but hard to tell for sure from a picture.


The Dodge speedo pinion gears are available new and used around $28 to $30, and used pinion supports come up on ebay frequently.
 
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Old 02-02-2017, 05:31 PM
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I have the NP435 in my two 1966 trucks and they are fine for what they are.

I also have the NV4500 in my 1999 Dodge Diesel and it is a very nice shifting transmission with a nice span between gears and, of course, synchro first and overdrive. I don't know as I care about the synchro reverse since I am usually at a dead stop anyway.

New Process became New Venture so really this is just the evolution of a transmission.

.
 
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Old 02-19-2017, 02:14 PM
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Why not just bolt on a new, short-shaft TKO-500 to the stock bellhousing behind that FE?

 
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Old 02-19-2017, 04:06 PM
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A TKO 500 might work depending on several things: What do you want the truck to do? If cruise around, it would probably be fine. If tow or carry heavy stuff, it might not. Rear axle ratio help plays a part. And how the engine is cammed as in where does it start making torque in the rev range. The 390 in my F100 makes lots of torque at 2000 rpms and has access to a 5.61 first gear if it needs it although I usually start off in 2nd gear, 3.04 to 1). The 427 in my '63 Galaxie, which has a TKO 500 (3.27 1st gear), doesn't start making a lot of torque until about 3400 rpms, so even with 3.89 gears, I have to slip the clutch a little starting off from idle rpms. So whether a TKO would work for you kinda depends on how you plan to use your truck.
 

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