NV 3550 SWAP DOS AND DON'TS, Regrets?

[FyreBronc]

Hey, thinking about doing a NV 3550 swap for the three speed, to make my 74 more usefull. I like the idea of driving to the trail, not trailering. Any body who has done the swap, would you do it again? Regret not going with the 4500? I'm going to run 35's with a near stock motor and moderate wheeling, just looking to the masters before sinking the coin. Any suggestions would be great. Thanks in advance!

 

[broncnaz]

Havent done that swap but what axle gearing are you going to run? It will need to be low enough to allow use of the OD which will also help lowspeed stuff and keep the motor in its torque range.

 

[904Bronco]

I converted my 77EB from a C4 to NV3550... Been very happy with the conversion and would recommend it ;D

http://classicbroncos.com/forums/showthread.php?t=112548&highlight=nv3550

 

[cgbexec]

I am running 4:56 gears, 35's and the NV3550. I would easily do it over and I recommend it highly. For street driving and moderate wheeling the NV3550 is perfect. If I was building a Bronco for more serious off road stuff, then I may have gone to the NV4550. My truck will see only mild to moderate stuff, so no need for the heavier trans.

 

[bigmuddy]

Don't forget the ZF tranny if your looking to do serious trail running.


Ben

 

[FyreBronc]

I was thinking running a 4.10 - 4.56 ratio in the pumkins. When you say moderate wheeling, do you mean mostly trail running with occasional rock crawling? This is my intention. Obviously I'm not looking for guaruntees just your experiences.

Ben how do you like the ZF? Does it shift well? How did the install go? i had not considered it due to the popularity of the 3550 and the almost turn-key install. If memory serves it is a HD trans, does it have OD? Might be right.

 

[cgbexec]

35" tires and I would run 4:56s.

My idea of moderate wheeling is street, dirt trail, sand, lite mud and some light rock crawling. If you are building for expert rock crawling courses, then you need something beefier.

The NV3550 can probably handle some rough stuff, but you should be carefull with the pedal so as not to stress anthing too hard. You would rather break an axel than the transmission. If you are running Dana 60's then the NV3550 is not for you.

 

[FyreBronc]

Yeah, no D60's for this kid. At least no yet. I was really looking to avoid the clunky HD trans feel but definitely want the OD. 35s, 4.56s stock to mild 302, can the 3550 take it?

 

[cgbexec]

The NV3550 is supposedly rated to 400HP. I'm running 330 HP and it seems to be a perfect combination.

The stock 3 speed was nearly undrivable. First gear was too high. I had to feather the clutch pedal and the gas pedal to keep the engine from stalling. Second gear was also just a tad high. 3 gear was fine if you never go over 45 MPH.

 

[FyreBronc]

Don't forget the bruises to your right leg when shifting!

 

[cgbexec]

Don't forget the bruises to your right leg when shifting!

Mine was a stock colum shifter and not on the floor.

 

[DRBRONCO69]

I did the swap about a year ago from 3 speed to NV3550. All I can say is I love it and would definitely recommend it. I run 37" tires and 4.56 gears. I use mine both on the street and trails. The overdrive is great and I have had mine on the E-Way at 80MPH with no problems. I would however like to go up in gear ratio to either 4.88 or 5.13 for a lower 1st gear ratio. I really don't need to do 80 on the tollway anyhow. Also, no more bruises on the right leg.

 

[bigmuddy]

Fyrebronc, I love the ZF with the 35's and 4.56 gears and 5.0. Yes it does have an OD. It has the granny low first gear too, so I take off in second. Truthfully if I am at even a slight roll I can take off in 3rd with little issue. When offroad the first gear granny is more than enough low end for any crawling I do. The 3550 is a much easier install from what I understand and will go in a bronco with no body lift which is nice. If I had a street only bronco I would go with the 3550 as the gear splits are said to be much more sporty than the ZF which is more truck like.

DRBRONCO69, to each their own but if I wanted a better crawling gear I swap gears in the D-20 or go to some other T-case.

Ben

 

[FyreBronc]

DRBronc- this set up sounds like the ideal set up for me but w/35's.

Big Muddy- I would love to go this route 37-40's d-60's and a hot 351 but it is not as practical now...... Maybe in the future. Thanks for your insight as that was what i was looking for. Actual end user opinions.

You guys rock!

 

[broncnaz]

Go with at least the 4.56 gearing you might even want 4.88's since you will have OD.
I like the ZF tranny over the 3550 for a couple of reasons 1 the lower first gear 2 dont need to order a separate clutch disc when you need a new clutch. Not sure on total cost differances as driveshafts will have to be modified with the ZF but I picked up mine for $150 and have seen others about the same price. Usually dont see 3550s any where close to that price.
On the side of the 3550 no driveshafts mods is about the only thing that would sell me on it over a ZF.

 

[skeltic]

Good tranny choice, but be aware of the great pumkin

I put in an nv4500 same gears the 3550s. I have 4.88's and ride on 35's . I would say if I was going to stay with the 35's I would rather have 4.56's or smaller the 4.88's require a lot of shifting at low speed's and even with the od it rev's too high for me at 60 or 65.
I am going to put some 38's on if I can get the scratch together.

 

[FyreBronc]

Gottcha, yeah gonna go w/35s and i think 4.56s unless i find some other contradictory info. Thanks for helpin a brother out

I put in an nv4500 same gears the 3550s. I have 4.88's and ride on 35's . I would say if I was going to stay with the 35's I would rather have 4.56's or smaller the 4.88's require a lot of shifting at low speed's and even with the od it rev's too high for me at 60 or 65.
I am going to put some 38's on if I can get the scratch together.