73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Wheels & Tires => Topic started by: johndeeregreg4 on September 16, 2019, 02:33:36 pm

Title: 3.42 10 bolt max tire size
Post by: johndeeregreg4 on September 16, 2019, 02:33:36 pm

I’m lookin to put on a 6” lift in my K10 with 3.42 gears which would mean 35’s however, I have been told that’s gonna rob my truck of power even with a 350 and TH400 tranny. My other option is a 4” lift with 33’s. What’s the max tire size I can run with my setup?


Sent from my iPhone using Tapatalk

Title: Re: 3.42 10 bolt max tire size
Post by: JohnnyPopper on September 16, 2019, 03:25:48 pm

What year is your K10?

Are the stock size 31" or what are you running currently?

Title: Re: 3.42 10 bolt max tire size
Post by: johndeeregreg4 on September 16, 2019, 03:30:36 pm

It’s an 85 and yes I’m running 31x10.5x15


Sent from my iPhone using Tapatalk

Title: Re: 3.42 10 bolt max tire size
Post by: Irish_Alley on September 17, 2019, 07:07:17 am

any increase in tire size will rob you from the take off power you used to have. that being said your rpms at cruising will be lower. ive seen people run 38s on that low gear ratio and while its ok for road use i wouldnt run it in the mud pit but then even if you find you need the rpms you can always shift into 4 low. just wouldnt do it on the road

Title: Re: 3.42 10 bolt max tire size
Post by: johndeeregreg4 on September 17, 2019, 07:44:04 am

Ok good to know! The thing I’m also concerned about is the strain that the tires will cause on the drivetrain. Is it enough to destroy the diff or tranny/ both?


Sent from my iPhone using Tapatalk

Title: Re: 3.42 10 bolt max tire size
Post by: Irish_Alley on September 17, 2019, 11:02:29 am

if youre not abusing it then no. the th400 will be able to handle the 35s. the OD in the 700r4 is known to burn up due to the larger tires but you wont have that issue. as far as the axle youll be ok, but then if you abuse it then something might give sooner or later

Title: Re: 3.42 10 bolt max tire size
Post by: JohnnyPopper on September 17, 2019, 12:55:11 pm

The weak link is the driveshaft and U-joints, regular and CV. (constant velocity- which I am derelict to find a lube fitting tip to get into those tight zerk fittings!)

If you have the type that can be lubed up, stay on it along with the spline joints, front and back.

Title: Re: 3.42 10 bolt max tire size
Post by: Irish_Alley on September 17, 2019, 01:48:51 pm

yeah forgot about the front driveshaft. as you lift it up to the 6" youll be maxing out the front driveshaft, it will still work ok but after some time in 4wd the splines will start wearing down because the spline contact is very min. but again i think its going to depend on how hard you drive it in 4wd. though it seams most people who run 38s and 6" lift without a new front shaft will tend to see this issue more than those running 35s