Ring & Pinion 93 Gmc 3500 6.5 Turbo Diesel Stock

[Austid09]

I have stock 4.10 (GT5 Rpo Code)ring and pinion gears if i upgrade to 4.56 or even 4.88 how much top end will i lose i know i need to upgrade for hauling heavy loads i figured that out this past weekend when i was doing 35 mph up a not so steep hill my dad has a 04 dodge 3500 cummings turbo that will pull the load i was pulling with torque to spare but what I'm wondering is just how much top end do you lose on a upgrade like this i know i cant argue with the fact i need the upgrade i just do not want to lose too much top end to where i cannot cruise down the interstate without bouncing off the rev limiter the price on the gears are about the same but i don't want buy both sets and waist the cash.... Thanks Everyone!

[DaveBr]

If you want more power you need to get rid of the factory exhaust. On the 93 the turbo down pipe is severly restricted which causes excessive heat and back pressure in your engine. Kennedy Diesel sells a good system you can install yourself.

There is a snorkel between the inner and outer fender that is attached to your filter box that must be removed. You must take the filter box off to get it out. This will allow your turbo to push more air in that asthmatic engine. This will be more effective than a gear change.

There are other things you can do for more power but you would have to get EGT and boost gauges installed first.

Welcome to the page!

[THEFERMANATOR]

4.10's already have these engines turning alot of RPM's. Does this truck tow all the time or just every now and again? If it was a daily truck for towing then 4.56's could go in it, but running empty will not be fun as she wil lbe turnin some R's. I would do teh basic mods to her first and go from there.

[bobt]

I had a '93 ext cab 3500 dually with 6.5/4L80E and 4.10 rear. I ran stock size tires, 225/75R/16, and at 65 mph, my tach said I was turning 2450 rpm. I did a number of things, including gauges, complete larger exhaust, the '97 cooling mods, Kennedy fan clutch, eight blade fan, Heath manual turbo boost control, and intercooler, and I achieved a considerable gain in power. All these items were added to get more power without sacrificing durability. If you change rear ends, the more revs you have to turn to get somewhere, the less life left in your engine. Hope my opinion gives you options to consider.
Good luck,
Bob

[Austid09]

Thanks Ya'll!!! Ill Do Some Performance up grades first i do plan to take trips with this truck.Sometimes i will be hauling very heavy loads i will often be hauling around 15-20000 lbs (Gooseneck)

Thanks Again!

[DaveBr]

Just a word of caution. What you are hauling is a lot of weight. The early 6.5's have cooling issues so you might want to upgrade your cooling system. 1997 GM came out with dual thermostats, a hi volume water pump and an eight blade fan. Kennedy diesel sells a cluch fan that kicks in at 180* F. You should seriously look into these upgrades.

[bobt]

Austin, If you are going to pull 15K - 20K very often, I don't think you are going to be satisfied even if you do the upgrades I listed previously. I carried a 4000# cabover camper on my '93 and towed a Jeep Wrangler (4000#?) behind. Practically all my 115,000 miles were interstate highway miles. Level running and up to a medium grade it would handle OK, but anything more than a medium grade would slow me down. Significant headwinds would also give me the fits. There are ways to get more power out of a '93 than I did, but to do so gets into areas that possibly reduce durability.
Bob

[More Power]

Thanks Ya'll!!! Ill Do Some Performance up grades first i do plan to take trips with this truck.Sometimes i will be hauling very heavy loads i will often be hauling around 15-20000 lbs (Gooseneck)

Thanks Again!

The highest factory tow rating for the 1993 model year GM pickups was for the C3500 2WD standard cab longbox dually, which was rated for an 8500-lb trailer. I don't think you'll be satisfied with the ability of a truck, having an 8500-lb factory tow rating, while towing a 15-20K trailer...

The newer trucks, like the Duramax, are equipped with an automatic transmission that is rated for a gross combined vehicle weight (truck & trailer) of 26,000-lbs (when installed in a medium-duty truck). That's just the transmission. The 2500HD/3500 GM trucks are rated for 21,000-23,000 lbs GCVW (combined truck & trailer weight) because they have the transmission, brakes, cooling system, chassis and engine power that were designed to handle it.

The pickup truck world has changed a lot since the beginning of the 1990s when diesel pickups largely didn't have turbochargers. There was no Powerstroke in 1993, and Ford's 7.3L IDI diesel was non-turbo. The Dodge Cummins was delivering an anemic 140-hp, and the new 190-hp 6.5L TD was the hot-rod of the group. Still, none of them could comfortably tow loads weighing more than about 4 tons - especially once the Federally mandated 55-mph speed limit ended.

When loads are kept within the design limits of the chassis and powertrain, the 6.5 can perform very well. That's where it does best...

Jim

[6.5 Detroit Diesel]

The highest factory tow rating for the 1993 model year GM pickups was for the C3500 2WD standard cab longbox dually, which was rated for an 8500-lb trailer. I don't think you'll be satisfied with the ability of a truck, having an 8500-lb factory tow rating, while towing a 15-20K trailer...



i think i will have to respectfully disagree on this. while the factory rated weight is 8500 lbs, i think almost anyone will agree these are rather low. while 15,000 to 20,000 lbs is a very massive amount of weight, towing 10-12,000 pounds in a HD2500 or 3500 is not hard at all, given a ratio of 3.73 or higher. i have towed a trailer that consistently weighed 10,000+ pounds for the last few years. the truck handled it fine.

the 93 with 4.10's towed a 16k trailer. yea the engine worked hard, but the trailer was set up for the weight, braking and suspension were not a problem.

like i said, i don't it is the best choice for towing close to ten tons, but it can handle seven or eight tons allright. just dont go dropping 4000lbs on your hitch and you should be okay.

i would keep the 4.10's. they are a good gearset. the revs are a little high at highway speed, but not unreasonable. going with 4.56's/ 4.88's, you won't have much choice but to scream along at high revs at highway speeds.

[6.5 Detroit Diesel]

sorry, i should have added this in as well. just read MP's response.

like everyone has said on here, best thing you can do to help your truck out is first do some engine mods. exhaust and dp need upgrading.

follow that up with the intake, take out that snorkel.

good airfilter will go a long ways.

tweak the IP and do a turbomaster setup. do at least a pyrometer with those upgrades. keeping those temperatures as low as possible, especially while towing heavy loads will let you make more then one trip with a heavy trailer!

another setup you could look into is water injection for when you are under heavy load and wanting to keep that engine as cool as possible.