gearing for 35's

[cs29ff12]

im wanting to run 35's on my 71 but not sure of the gearing that is needed for that size tires. im running a 351w, np435, dana 20 with 2" body lift and 2.5 suspension. I have looked and am comming up empty on an answer. thanks for all the help.

 

[garberz]

I run 4.56's with my 35's. I'm still able to run decent on the fwy. I drive about 60-65mph, which is just a bit over 3000 rpm. It's decent on the trail, although I'd still like a lower transfer case ratio. The 435 has a very low 1st gear, I'd say your right on the fence between 4.56's and 4.11's. If your mostly street and highway, 4.11's will help for a nice cruising speed. If you spend more time off road than street, then the 4.56's would be a good choice with 35's.

 

[cs29ff12]

more street but love to go out and play in the mud and trails

 

[Bigbird]

http://www.grimmjeeper.com/gears.html

Here you go!!!

 

[broncnaz]

You could get by with 4.10s give you better low end and be at around 3000 rpm on the hiway. Some people will say 3.50s are fine since you have the np435 and a 351 and while it will work I just feel its to hard on the clutch and you may need to actually use 1st gear to take off all the time.
If you dont do much hi speed hiway driving then 4.30 or 4.56 would be the ticket

 

[blubuckaroo]

I'd say 4.11s would be best for multi-use with your 35" tires.

 

[Hozr]

35's, ZF, Dana 20, 4.11's

2000 rpm @ 70 mph

Zf has the granny low too

 

[Apogee]

Given that you have a 351W, I'd probably go 4.11 or 4.30 with your NP435. If you see yourself potentially swapping to an overdrive transmission in the future, then I'd step up to either 4.56 or 4.88 and live with it until then.

 

[cs29ff12]

thanks everyone your help is greatly appreciated.

 

[Broncobowsher]

4.10 would be the most highway friendly gear I would recomend.
4.56 would be the steepest gear I would recomend for any highway use.
4.30 would be my personal pick

Based on 1:1 top gear in a NP435 on 35s and a 351.

 

[wildbill]

If you like a little go then you will need 4:56's with 35" tires. 4:11's work well with 33"s good luck with your choice. Bill %)

 

[True North]

4/10 5.o c4 35's. Mostly street and it works fine. If I was going to start over I would go 4/30's.

 

[bmc69]

I run 4.10 gears in a '76 with 35" tires and a '78 with 37" tires (even had 38s on it for a while). Works great for all around, but only because both rigs have NP-435 trannies with the super low granny gear.

If I was running an OD tranny, I would go with the 4.56 gears and 35s..

 

[Timmy390]

4:11's work well with 33"s good luck with your choice. Bill %)

Yes they do.......

Tim

 

[tw322]

I bought mine with 4.11's from the p.o. It has a 351 and an aod and it works well for me. Not a rock crawler but good all around.

 

[blubuckaroo]

If I were going to install 35" or larger tires, I think there are more important important issues to consider than the final highway gear ratio. You also need to consider first gear. If it's too high, you'll wear the clutch or auto transmission clutch prematurely. Also, at 35" even stock disc brakes and 28 spline axles are entering the realm of inadequate.

 

[cs29ff12]

well i think it will be the 4.11's. thanks so much for all of your help

 

[Casey835]

I like my 4.11s and 35s. It gets me to 70 mph nicely.

 

[Lmfp]

I vote 4.30 for all around. Im stuck trying to decide on this myself because i might do an overdrive eventually.

 

[Broncobowsher]

I vote 4.30 for all around. Im stuck trying to decide on this myself because i might do an overdrive eventually.

Gearing with an overdrive and gearing without are completely different. Trying to do a compromise gear will simply get you a gear that sucks either way.