List ur tire size, and what rpm u run at 60, and 70.... I need to make a decision on tires so hopefully some of u have different sizes like 33's, and 35's so It can help me make a decision.. thanks

 

I had 35's and ran about 21-2200

 

215-85-16 is my size. at 60 i run a tad over 2000. at 70 about 2300

 

I have the stock 17" tires and rims and at 70 mph my tach sits at 2150-2200 rpm.

 

on 265/75/16's I run 2200rpm.

 

so it looks like the only tire that really makes a big difference in rpms is 35's? According to a tire calculator, with 35's and 4.10's it should be just like 3.54's.

 

My 99 is an auto so i dont no how much difference it make between the 5sp. I run 2000rpm at 72, 60 is in the 1700 area, That is comparable to our 6sp and 373s, its with in 50 rpms.

 

The auto will be 200RPM slower than a 5speed. You have a manual, so with 35's, it will turn 2200. That's what I see with my 98.

 

Coming right out of the transmission, do the autos/manuals turn different rpms at "X" engine RPM in their highest gear?

 

I had a 47rh in my truck, then swapped to a 5spd and they both turn right around 2000rpm at 60mph, the auto might have 50rpms less, but not real noticable on the higway.

Dieselrob thats exactly what i'm hoping for, right around 2000 at 70. I guess the search continues for the right 35" tire and spacer for my dually. I wish there were some tried and true setup like 35x12.5 with 2" spacers, but nobody seems to know for sure about clearence between the duallys. If I could get a 35x11.5 that would be nice for the back, but u can't except Super swamper, they even make a 35x10.somthing

 

my 97 on 265's runs just above 2000 at 65 and 2200 at 70. I really wish I had the 3.54's!

 

at 70 mph with 285's/75/16's, I turn 2200 rpms with 4:10's, at ----75---- with my Gear Vendors OVERDRIVE unit ON, I turn 1800 rpms That rocks


1997 CTD 2500 4X4 ex-cab long box, 235,000 miles, gear vendors 8 speed overdrive, stage 5 TST fuel plate, 4" exhaust, 370 injectors, full DTT auto trans, turbo silencer MIA, X-monitor digital guages, 4:10 gears w/ limited slip, new style tow mirrors, stock turbo and pump

2004.5 CTD 2500 4X4 4 door long box, silencer MIA,

 

how much is a gear vendors overdrive?

 

$2495.00

According to some pages that I could find.

Think you're better off getting some 3.55 axles to swap .

 

35" tires are on the way, just gotta find the right spacers to use... :-D