gear swap.....3.08 to 3.42

[Northern Wrangler 6.2]

I have 3.08 gears in my 86 C10, 6.2 with 700R4, running 255/70/15 tires (29" approx). and I was thinking of swapping in 3.42 gears so it doesn't lug at slower towing speeds. I've been running it in drive when I have the camper on or a 2000ish # boat. Will the 3.42s help all around. My 85 K10 has 3.42s with 31" tires and works well.

opinions ?

Kev

[john8662]

The orig. tires were 235/75 which are ~ 28.878 in diameter

Your current tires are 29.055"

Not a huge change...

I'd think the gear change to 3.42 would be a good move considering you do some pulling. 3.08's are a great running empty in a single cab 1/2 ton truck getting 24+ mpg kind of gear. Not so peppy pulling something. You're doing the right thing anyways pulling in 3rd (drive) verses OD.

I guess it all depends on how much $$ you wanna spend, tires or gears?

I vote gears...

I've got essentially the same truck with 3.73's and 30.9's, turns 2k at 70mph...

[Northern Wrangler 6.2]

3.73....hmm.... I ordered a set of 3.42s from LMC for $200.00...and I have to go in anyways to changed a frigged axle shaft ($99) from LMC...so I figured, what the heck....I'll likely change to 30 or 31" tires soon. I wanted the
3.42s for fuel mileage and power, as a happy medium (I like to drive fast too..)....

[NH2112]

3.08 to 3.42 is about an 11% change, going up to 31" tires is about a 6% change and will basically cut in half any benefits you get from the gear swap. I'd either keep the 255-70-15s with the 3.42s (235-75-15 may be better, they're narrower and have less rolling resistance) or go with 3.73s if you want to run 31s.