35" or 315/75R16 tires + 3.42 gears...How much performance am i loosing?

[Darkrider]

Ok....Now that i have seen all these bigger GMTs (K25/3500s) lifted on body lifts and cranked and clearing 35-37" tires i have been giving some serious thought to going this route with my K3500. Now my truck currently has the 3.42 gearing and a TH400 3 speed in it. How badly will running a 315/75R16 or 35" tire affect the trucks performance? Is it a livable set up for awhile till i can afford to regear the diffs? Or am i better off just going with a 2" lift and staying with a 32-33" tire?

 

[badazzbulldog]

are you sure its 3.42's and not 4.10's my 88 3500 was the same drivetrain setup with 4.10's

 

[Darkrider]

are you sure its 3.42's and not 4.10's my 88 3500 was the same drivetrain setup with 4.10's

According to the RPOs and the trucks vin it was originally equipped with 3:42s and a 7.4 V8.

 

[Wagonbacker9]

my 2500 has 3.42s, and with the 285/75/16s its not unlivable, its definitely not FAST. I do have the 4l60e though..

 

[badazzbulldog]

it shouldnt be bad with the th400 with 35's

 

[ChrisAU]

Mine has 35's with 3.42's and the 700R4. Top speed is about 82 MPH, on level ground. I'm not joking lol.

 

[Wagonbacker9]

Mine has 35's with 3.42's and the 700R4. Top speed is about 82 MPH, on level ground. I'm not joking lol.

I've never tried to go above 75 or so (indicated.. so actual speed would be faster), but it felt like it had plenty of room left.

 

[ChrisAU]

I've never tried to go above 75 or so (indicated.. so actual speed would be faster), but it felt like it had plenty of room left.

Oh yeah it gets to 82ish quickly. But once there, thats it ha. With your 33's Id think you could go substantially faster, but not sure how to do the math there.

 

[Darkrider]

So in short its a livable set up i mostly just loose some top end for highway driving?

 

[ChrisAU]

Oh yeah I think mine is fine for every day driving. I feel that the lower gears give me more control over my power band, especially down low.