what is a good gear ratio for a 6.2

[6.2L Driver]

I have a 82 6.2 half tone four wheel drive truck, with a 700th tranny, and a banks turbo soon i hope. What is a good grear ratio for this truck. Any sugestions, thanks

[dieselcrawler]

Hmm.. that kinda depends... What size tire do you run, what do you haul with your truck?.... I have 4.56 gears, and they are too tall... want 5.13's, but I also run 40" tall tires!!! I'm sure some others will have some advice for you if you run stock size tires, but if you have the OD trans, the 700R4, my guess is that 3.73's or there about should do good for you... so long as you don't go over about a 31" tire. If you go to 33"'s, you'll be wishin' for 4.10's. But let's see what every one else has to say...
Greg

[britannic]

I'm running 33" tires with 4.56 diffs and the 700R4. 60mph is slightly under 2000rpm - this gives me an overall average mpg of 15-17 in the mountains. See my sig for details on power upgrades.

This ratio works well for my style of driving and the area in which I live. The truck spends 30% of it's time 4 wheeling on the logging trails and the rest running on mountain roads and freeways (and of course, burning off the odd "passed and curious" go faster mobiles :D ).

Work out where your truck will do most its work and how you like to drive it and then compute your preferred gear ratio/tire sizes at: www.4lo.com. (http://www.4lo.com.)

[6.2L Driver]

here is alittle more info, tires are 31 inch most of my driving will be highway i think. It was my old farm truck for about 650 000 km, about 300000 in four wheel drive. I am rebuilding this truck and going to ritire it from farm use. I want a truck the will cruise at 70 to80 mile an hour down the highway with no problem. And then guess plow mud in the field on the odd time cause it is so much fun. thanks for any sugestions

[88 K30]

As was pointed out, it really depends on what you want. Do you desire good fuel mileage or good towing power, or the best combination of both? For very good mileage and highway cruising with the 6.2 and pretty much stock-sized tires, you really can't beat 3.42's, IMHO. They are a great gear for a 6.2 with a 700R4 that doesn't do a lot of heavy towing. Of course, with a 700R4, you really have plenty of options. 75 mph is easily attainable with 4.56's, and you get one hell of a crawl ratio in low range (36.4:1 with an NP208)! 4.10's and 3.73's also fit the bill well. I have 3.73's in my old gasser with a 700R4/NP208, and they are a great all around gear, especially when you have OD.

[Dieselboy]

One bad combination: 4.10s and 35s :mad:

For stock tires about 31" tall, 3.73s sound like a winner to me. That's about what we run on my father's 96 6.5TD. It seems to be a great overall combination for towing and zipping around town.

Personally, I want to run 5.13s and 37s on my suburban for power and off-road prowess. :D

[arveetek]

For your application, I would suggest 3.42's. I had those in my pickup until I went with 4.10's for more power. I have 28" tires and 4.10's and really love it, but I wouldn't want to run it at 80 mph for long periods of time.

I think 3.42's would be good.

What do you have now, 3.08's? 3.73's?

Casey

[john8662]

I've got 31's on my 86 2WD and 3.08 gears. I would highly recommend the 3.42's. I like the RPM range with 3.42's from other trucks I've driven. I run 80 all the time with mine non turbo'ed, but on a windy day, I wish I had the 3.42's. When I get a chance I will change to 3.42 for in town driving being stop and go.

[Professor]

I'm running 31s and the 700R4. Mine came with 3.42s but when I rebuilt the rear, I changed to a 3.73 and have not regretted it one bit.

[TanM998]

I have 37" tires with a 2.53 ring gear and 1.92:1 gear reduction at the wheels... overall axle ratio is a 4.86, and I don't have a tach but my guess would be that I am running around 2,300 - 2,600 RPMs. My govenor kicks in at about 74mph (according to my GPS).

Scott

[diesel65]

My truck originally came with 3.08's then I changed to 3.42 now I have 3.73's in my 85 and it works well.
If you are going to install a Banks turbo system use the 3.73 gears, the Banks turbo works better when you have a few more revs.
Now I am working on the 97, converting from 3.42 to 3.73.

[Dieselboy]

One good quote to remember:

"I always recommend going for MORE GEAR - you will feel it in the seat of your pants, and enjoy it ! !" - CleviteKid

[cschneider]

To address a previous comment, I believe the governor kicks in around 3400 RPM which is too high for these engines to run for any extended period of time, I'd be careful. I have switched from 3.73s to 3.42s and have no complaints. I have the banks with HO injectors and a 4911 pump but I also have the TH400. I wouldn't mind having a Gear Vendors to go higher but don't have the money right now.