33's and c4? with 4.11 or 3.50

[MPG_Bronco]

I see other threads, but don't want to high-jack them.

I have 4.56 gears with 35's, it's nice, 3k+ rpm at 65mph yeah it's high, but it's expected

I want 4.11 gears with 33's, keep the rpm about the same, screw mpg, I want to go what's best for engine and trans.

but made a deal to go 3.50's with 33's, i guess 2450 @ 65mph,
this truck will be driven alot, for any excuse, mostly me alone. it will see dirt, but mostly city and road to be honest, no deep mud or large rocks.

I've been talked into 3.50's are best all around with 33's. I'm in AZ so city is flat. but the trails won't be.

I have a 5.0 HP engine (i think mustang) with c4 that has transgo shift kit.

Maybe a good tranny cooler with elec fan will help in AZ's 110+ summer heat. I just don't want to cook parts.

how big of hole will be in my foot?

 

[broncnaz]

Pretty much as was said in all the other posts you've read it will work its just not the best stop and go driving may put more heat into the tranny. The hiway stuff is no problem. AS was said people have been running that combo for many years as few people regear when going to 33in tires.

 

[garberz]

......screw mpg, I want to go what's best for engine and trans.

That's ironic and quite funny.

 

[blubuckaroo]

I see other threads, but don't want to high-jack them.

I have 4.56 gears with 35's, it's nice, 3k+ rpm at 65mph yeah it's high, but it's expected

I want 4.11 gears with 33's, keep the rpm about the same, screw mpg, I want to go what's best for engine and trans.

but made a deal to go 3.50's with 33's, i guess 2450 @ 65mph,
this truck will be driven alot, for any excuse, mostly me alone. it will see dirt, but mostly city and road to be honest, no deep mud or large rocks.

I've been talked into 3.50's are best all around with 33's. I'm in AZ so city is flat. but the trails won't be.



I have a 5.0 HP engine (i think mustang) with c4 that has transgo shift kit.

Maybe a good tranny cooler with elec fan will help in AZ's 110+ summer heat. I just don't want to cook parts.

how big of hole will be in my foot?

Don't pick your gear ratio for the highway alone. Both the factory three speeds and C4 have the highers first and second gear ratios available. You're performance is going to be poopy if you select for the highway. Stay on the low side. You can always slow down.

 

[Broncobowsher]

4.11s were great with 33s. Before I did 4.88s and overdrive I found it a very happy combination. Drove very good, trips to Flagstaff for the cinders in the middle of summer was no problem (back when the Stampede was in the cinders).

I would pick 4.11s, maybe 3.90s. The 3.92 is as far back as you can go with the existing front carrier in the front.

The first Bronco had 3.50s. Felt the 31s were really pushing it for that gear. I was so happy when the second Bronco started with 4.11s

Trying to push down the RPMs with a non-lockup convertor just makes the trans work harder and hotter.

If possible I like to suggest doing just the rear axle first. Take it for a test drive.
Like it, do the front to match.
Don't like it, you only have one easy 3rd member to redo.

 

[rwill]

I had 33's and c4, switched to 4:11 and love it. Would not go bsck to 3:50's if you paid me.

 

[BlackCat4]

I have 33" with 3:50 im not sure what y'all are saying is it good or bad Its my DD but I off road too...I put 100mil a day..what do y'all thank..I only get 6 mpg was hopeing to get better...

 

[bronconut73]

I ran 33's and 3.50 gears for twenty years or more. Always thought it was fine. Then I went to 4.11's. For such a small amount of gearing difference it makes a huge seat of the pants difference.
If anything my mpg improved.
Performance is much better.
I can accelerate easily without the tranny needing to downshift and the shift points seem to be dead on now.
Yup. I would not go back to 3.50's. Never knew what I was missing.

 

[broncnaz]

I still run 3.50's and 33's although I have a NP435 so I have better lower gearing. But hiway its fine. Of course my engine is not stock either so that helps the power. 4.10's would be better if you do a lot of mountain driving but 3.50's will still work.

Its really the take offs and lower speed driving with a automatic 3.50 gears and 33in tires that puts more strain on the tranny than if you had better gearing. Again mmany people thru the years have run the 3.50/33in combo with little issue. Just dont expect it to be a tire burner or for the transmission to last as long as it should.

 

[Lmfp]

I'm on the wall with a re gear. I have a 351 so I have more bottom end... but... I have to do alot of Highway driving. I know I'd have alot more performance in town but Heck I dont want my motor screaming. I'd love to know what it would do though. already managed a second gear burnout with a c4, 33s, and 3.50 gears. One day ill be able to do an OD trans.

 

[HoldMyPocket]

I've been daily driving a built 302, c4, 35's, and 3.50's with a detroit in the rear for a couple of years. At one point I was doing 80 miles a day for a year in traffic. Works just fine, gets 11mpg (sometimes more if I don't drive like a maniac). This thing sees the dirt like 2-3 times a year if that.

 

[Broncobowsher]

For those with the 3.50 gears, have you ever tried 4.11s?

The point I am trying to make is 3.50s work and they are OK. But those who have had both 3.50 and 4.11 gears, those who know what both flavors taste like, it looks like 4.11s are preferred. Has anyone tried both gears and gone with the 3.50s?

 

[kntr]

It also depends on the 33" tires you are running. My 33x10.50s are small and light.

 

[BluebroncoNC]

I have a 3.50 geared c4 stock truck running on 33" tires. I've taken a few rides in 4.11 geared 33" tired vehicles and the difference is very noticeable, seat of the pants wise. I will be making a switch but not sure I will go all the way to 4.11 as I mainly drive highway with my truck. Was thinking 3.90's.

But, yea seat of the pants, the 3.50 is a dog, but man 80 down the interstate sure is nice.

 

[MPG_Bronco]

I have the same opinion that seems to be the general discussion. no one is vouching for the 3.50's OVER using the 4.11's.

I called around and found a local shop that can do the 4.11 OR 3.92 gears for the same price as the used 3.50 gears.

With the c4 I expect a couple extra 200-300 rpm to keep it at speed. these RPM's are speculation and not exact. but I could see the rough change between gear sets.

@65mph
tire---gear-------------rpm-------------change from current rpm
35----4.56-------------2847 (current)----0
33----4.11-------------2721-------------126
33----3.92-------------2595-------------252
33----3.73-------------2470-------------377
33----3.50-------------2317-------------530

oh and I'll be running 33x12.50r15's probably some M/T or A/T

I haven't made up my mind yet, I think 3.92's would be very good... but at least I'm making progress

 

[BluebroncoNC]

I have the same opinion that seems to be the general discussion. no one is vouching for the 3.50's OVER using the 4.11's.

I called around and found a local shop that can do the 4.11 OR 3.92 gears for the same price as the used 3.50 gears.

With the c4 I expect a couple extra 200-300 rpm to keep it at speed. these RPM's are speculation and not exact. but I could see the rough change between gear sets.

@65mph
tire---gear-------------rpm-------------change from current rpm
35----4.56-------------2847 (current)----0
33----4.11-------------2721-------------126
33----3.92-------------2595-------------252
33----3.73-------------2470-------------377
33----3.50-------------2317-------------530

oh and I'll be running 33x12.50r15's probably some M/T or A/T

I haven't made up my mind yet, I think 3.92's would be very good... but at least I'm making progress

I'm thinking, if you make your decision before Townsend, then come to Townsend, then take me for a ride, I can then make my decision. ;D

 

[broncodriver99]

I just finished my gear swap from 3.50 to 4.11. I am running 33's and the stock 3 speed manual and it made a very noticeable difference. No more dragging the clutch to get going.

 

[Dan's73]

I've been thinking of making the gearing switch too, from 3.50 to 3.92/4.11....be interested in who you're talking to locally (Phoenix area?) and what sort of pricing they're giving you. If you don't mind sharing, please PM me.

I've had 3.50 & 4.11 gearing with 33" tires, stock 3 speed & C4 too, and I truly appreciate both. At this point, for me, I'm wanting to get more of that "seat of the pants" feeling back that the 4.11's offer. Cruising speeds/rpms are nice on the freeway but I find myself doing less & less of that with my '73.

 

[ep67bro]

I had two broncos with the same motor and trans set up and the same wheel and tire size but one had 3.50 gears and one had 4.11 gears. On the hwy cruising couldn't tell much difference but from a dead stop the 4.11 truck pulled way better. Both were mild built 302s with C4 trans and 33x 12.5 x 15" Procomp Mt tires on 15 x 8" wide rims. both truck were a 1973 one had a 2.5 lift the other had a 3.5" lift.
I have 33s on my 67 with 3.50 gears but a I have a NP-435 trans. It fine on the hwy and even ok from a stop. I put 35s on it for a few days and it was a total dog off the line. I now have brand new 35s sitting in the shop but haven't put them on because I can afford a gear swap to 4.10!

 

[1sicbronconut]

Might be OK where you are at but the first time you make a drive up to Flagstaff you might be rethinking the 4.10 gears. I run 4.10 gears in my Luber with 33"x10.5" KM2's that are on the short side wishing I had gone with 4.56 a lot of the time but I do a lot of wheeling at higher altitudes also.