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1974 NP435 Tranny Swap to Automatic

Dukesford

New Member
Joined
Jan 3, 2008
Messages
3
It's a 1974 Bronco with a 302, 5.5 suspension lift, 35 tires, Front dana 44 and ford nine inch with 31 spline, ARB front and rear lockers.

It currently has the NP435 (granny gear + 3 more) and I want to swap out that and put an AOD, AODE or something else. I put a B&M AOD in my Mustang and basically bought 2 of them b/c of all the repairs it needed.

Where do you recommend I get one (links would be helpful), and I will also need to get the adapter too which i have found at various sites (400-500). Is their anything besides those that will work without major customization? I am not looking to spend a lot, i figured a built AOD plus adapter will cost 2000-2300.

How much can I get for the NP435 if its in good condition?

I am knew at 4x4ing and appreciate any help.
 

sprdv1

Contributor
REBEL
Joined
Mar 8, 2007
Messages
81,734
Welcome to the board. You will get great information here.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Before I go recomending anything (especially in the overdrive department) what gears do you have in the axles? The 302 will need tot turn some RPMs to punch a hole in the wind with a Bronco rolling on 35's.

After we get past that then I will offer my suggestions on what transmission to run.
 

GnisroH

Full Member
Joined
Mar 27, 2007
Messages
200
Loc.
Harrisonburg, VA
a rebuilt NP435 can bring anywhere from $300-400, add anywhere from $100-200 if the adapter from Advanced Adapters is intact on the tailshaft too...

If the 6 cyl. intermediate shaft was used, don't expect more than $400 or so...

...But I'm with everyone else...why no love for the NP435? With a good gear set, you shouldn't be using the clutch as much on the trail, is it a DD (Daily Driver) too?
 
OP
OP
D

Dukesford

New Member
Joined
Jan 3, 2008
Messages
3
They are 4.56 gears, and I would like to go a little faster on the highway at lower RPMs. I plan on 4wheeling and also taking it to the mtns to snowboard. Not a daily driver but I love to drive my toys.

It does make sense to keep the NP435, but with those gears and from what I have been told about the cost and difficulty of swaping gears with the ARB lockers I might as well get an AOD and keep the gears.

If not going to a Auto, what manuals would you all recommend? Would the Dodge NV4500 or NV3500 be the best or what?
 
Last edited:

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
4.56 gear and 35's. If you find a trans with a .70 OD (fairly mid OD ratio) that makes them act like 3.19 gears. Then you want to take it into the mountains.

My advise, leave it the way it is and keep your money in your pocket. Slow down a little and enjoy it the way it is. The little 302 can maintain 3500 RPM all day long. Adding an overdrive will drop the engine speed too low to be effective, so it will always be shifting back out again, overall making for a miserable driving experience.

For reference I am running 4.88 gears, .70 OD and only 33" tires with a torque built 351. That runs good and can cruise at 70 fairly well. Above that it can still push it, but it starts catching wind and becoming unstable. You are running bigger tires with less engine and less gear.
 
OP
OP
D

Dukesford

New Member
Joined
Jan 3, 2008
Messages
3
Thanks everyone, I'll keep it like it is for awhile and see if I am absolutely miserable or not. I look forward to trading ideas and experience with you all and learning a lot from you guys.

Thanks,

Travis
 
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