19 Closed Ratio Swap

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custom76

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Greeting from Afghanistan!

I am new to the forum and halfway new to older broncos. I have a 1976 that I did an on frame "restoration" Rebuilt 302, 3.5" Lift done right with new rear springs, adjustable tracbar, new radius arm bushings, blah blah.. Replaced the front floorboards and middle seat panel section. All new brake and fuel lines with new brakes and parts all the way around. Did whatever i could do in a one stall garage in base housing... I have not done any body work besides the dash, and floorboards but have plans for the body work when i get back. I am wanting to get rid of the 3 on the tree and go to a 4/5 speed. I have been doing alot of research and I know the swap forums have been written, but i have not been able to find a good answer for my question. I drive about 70% around town/highway and about 30% off road/mud. I currently have a mild 302, running 33" tires and what i believe is 3.55gears. I read the tag on the back before I left, i understand they could have been swapped, but i want to swap with 3.73 or something in the 4.10/4.11 range. ( will take advice on that as well) I am looking for different gearing in my next transmission. I understand the np435 is the most common swap, and easiest from what I read, but I also understand that it is not going to change my gearing besides giving me granny low which I am not sure I need. I know the NV3550 is going to be the best all around, or maybe the ZF, but I wasn't trying to spend $2,000 on the swap. I read on the novak-adapt website that the T19 with closed ratio has a gearing of 4.02,2.41,1.41,1. Is this gearing feasible for what I am wanting to do? I still think I would be getting a lower first gear than what I have now in the 3 speed at 2.99. What do you guys think about this and am I correct on the information I have so far? From there what is the best source to pull a T-19 closed ratio tranny from? And how do I identify it? Can I pull from a 2wd and 4wd truck and what would be differnce be or what would I need to do to make either one work? Any suggetions or information on this would be greatly appreciated!

Thanks

Will

 

Bully Bob

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Hi Will., welcome., & thank you for your service..!!! :)>-

BTW., great post..., leaves little questions, if any.

IMHO., the stock 3sp. is your best bet for your requirements, & then some.! Most 4sp. still have a 1:1 final (in 4th) all that equates to is a lot more shifting.

Most all the others (5sp.,etc) are bigger., heavier., req. drive-line changes, etc.

These set-ups work well for heavy wheel'n & rock banging..!!

You can count the rotations (dr.shaft-to-wheel) to get an the gear ratio but., with your tires & needs., I would put 456's in the diff's.

From there you'll be "happy as a clam" ..., have spent prob. less than $1000., with a lot less time, labor, & headaches.

You'll "feel" a performance & handling difference.., way more than a trannie swap.

Floor shift is the only way to go...the column shift is just awkward.

Throw on a good set of headers & you'll be hard to beat..!

You may get a number of diff. opinions.., 'cause that's what we're here for..!! >:D< <'>

Stay safe, & keep us posted on your decisions/results if you would. :-B

 
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custom76

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Bully Bob-

I thank you for you quick responce. I am still on my learning curve when it comes to transmissions,transfercases,gears and all of that. I am just wondering though, if I put 4.56s in the rear and stick with the same transmission, wont that dramaticly increase my RPMs on the highway? Right now in 3rd at 65mph I am running about 3800-4000RPMs.

Thanks,

Will

 

Bully Bob

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OMG..!!

You'll have to count the rotations..!!!

Only way I see that's poss. (4K RPM's) is if someone put 570's (or there 'bouts) in the diff's.

33's with 350's would get you approx. 2200-2500 RPM.

456's would get you around 3000+ RPM. (near the top of the power curve)

"I am still on my learning curve when it comes to transmissions,transfercases,gears and all of that."

Not to worry., we all have to start somewhere.

At the top/right on this home page...type in gear ratios in the search spot. lots of info. there.

 
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custom76

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I thought that it was high and thats why i was looking into another gear to grab onto. I put two different tacs on it to be sure i was getting a correct reading. I will have to count the rotations when i get back to see whats going on... If its got some high gears in it as it is, i will definatly drop down to a higher gear in the diffs.

 

Bully Bob

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Just for reference... the higher the # = "lower" gearing.

i.e. 456 is a "lower" gear than 350's.

EXAMPLE; 350's = 3.50 = 3 1/2 = "MEANS" for every 3 & 1/2 revolutions of

the drive shaft., you get 1 revolution of the wheel.

The "lower" the axle gears..... the more the RPM's will increase at a given speed.

Your (517+-) gears are what's winding your eng., prob. beyond its power curve. Not good for eng. life as well.

 
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