4.10 vs 4.56 gears

[wkpoor]

I've got a 2002 Chevy Express van 3500 I tow with. It currently has the 3.73 gear. I'm wanting to change. I've already talked to many and most have said 4.56 too low. But I'm afraid the 4.10 won't be enough of a change. I don't care about gas mileage because compared to the cost of a new diesel truck its a non issue. I'll never use that much gas! Anyway having never drivin a truck with 4.56 gears I don't know how the driveability will be on the highway. Will it be a screamin deamin or will it OK? I regularly tow 10-12,000 lbs.

 

[Diamondpilot]

What type of driving are you doing? If its mainly high way I would go with 4.10's or stay with the 3.73's but if its all stop and go the 4.56's may be a better choice. I had a F-150 with 4.10's gears that I used for nothing but stop and go and it got the same mileage as as the 3.73's equiped truck I traded in on it. The only place I noticed a difference was off the line. I am guessing that is where you will see the benefits also. Once you get the load rolling in most situations you will be ok with the 4.10's or 3.73's.

Chris

 

[wkpoor]

Its a combination of all types. Most of the time it is local towing on 2 lane roads. But each year a couple of times I do take a road trip. So being able to roll at 65 is important. I've ran the numbers. Without OD ,30" tires and 65MPH-3.73 - 2700rpms...4.10-3000rpms.... 4.56-3300rpms

 

[Diamondpilot]

Well you got there before I did. I looked on the net and found a few calculators to help figure out rpm's. If you have the motor the 4.10's would be fine I would guess. If the van is underpowered you may need the help of gearing. Like I said on the F-150 with the type of driving we did with it the mileage was the same. The reason I guess was it labored a lot less getting the load rolling.

Chris

 

[wkpoor]

Its got a 350 gaser.

 

[Diamondpilot]

Probably the best engine ever built but not to much on power in most applications from the factory. I would probably give the 4.10 gears a try. If you get into the 4.56 gears you may be pushing the limits of the engine and continued rpm's.


Chris

 

[CATMAN]

If you went with 4.56 gears, could you put on taller tires for the long road trips? Could you fit 33" tires on it under the fenders. This is an option that maybe you have or have not considered.

I run 5.27 gears with 33" tires with 5 speed manual overdrive in a '85 toyota 4x4 and am happy until I am doing 75-85 mph on a long trip. Also have 1988 Chevy 1 ton 4x4 with 4.10 gears and 454/turbo 400(no overdrive) and it has 33" tall tires on it. It handles loads well, but it doesn't like 80 mph from Seattle to Iowa. It runs fine, but I didn't like revving that 454 that long.​

 

[Builder]

I've got a 2002 Chevy Express van 3500 I tow with. It currently has the 3.73 gear. I'm wanting to change. I've already talked to many and most have said 4.56 too low. But I'm afraid the 4.10 won't be enough of a change. I don't care about gas mileage because compared to the cost of a new diesel truck its a non issue. I'll never use that much gas! Anyway having never drivin a truck with 4.56 gears I don't know how the driveability will be on the highway. Will it be a screamin deamin or will it OK? I regularly tow 10-12,000 lbs.

4.56's will be screamy on the highway. If you like to go 70, you'll be high up on the tach and gulping lots of gas. If you run mostly suburban stop/go, you won't really ind them too much.

I had a F-450 with 4.88's. I switched to 4.30's. They were a great gear for my application. Still pulled 16,000lbs off the bumper, but when unloaded, they didn't scream too much. Now that was with a highly modified 7.3L diesel.

See if you can slap a 4.30 ring & pinion in there. It might be just the gear you're looking for. It will definately make a 350 pull a trailer better for short trips. Long trips might be a different story.

4.56 or 4.88 is too low.

 

[bx23barry]

3300 rpm isn't a problem for a 350' but at 70-75 it will be screaming pretty good. But the gear calculator I use;
Gear Ratio Calculator
comes up with 3154 with 4.10s and 3507 with 4.56 with a 1-1 high and 30" tires.
You should have some kind of overdrive so your numbers may be right. I wouldn't be afraid of spinning that 350. It makes max torque at 4000rpm so 80% (where the "sweet spot" is) is 3200.

 

[machmeter62]

I've got a 2002 Chevy Express van 3500 I tow with. It currently has the 3.73 gear. I'm wanting to change. I've already talked to many and most have said 4.56 too low. But I'm afraid the 4.10 won't be enough of a change. I don't care about gas mileage because compared to the cost of a new diesel truck its a non issue. I'll never use that much gas! Anyway having never drivin a truck with 4.56 gears I don't know how the driveability will be on the highway. Will it be a screamin deamin or will it OK? I regularly tow 10-12,000 lbs.

If you plan on a long term usage of the van; you may want to go the "extra mile" and add an over/under gear box to your existing transmission, that will give you all the options for towing and mileage? I think the company is called GEAR-VENDORS? If not, someone here may chime in to correct me?