what size tires can i put on...

[784x4ron]

i have a 1978 chevy k10 3/4 ton 4x4 i,m putting a 3" body lift on it.can any one tell me what are the biggest 15"tires i can put on it with out cutting the finders down. i would like too put 35x12.5x15..it,s still stock and i have 33x11.5x15" on it now.  thank you...

[roundedline]

You need 4" of lift to clear 35x12.5's without rubbing.  Technically you shouldn't be able to clear 33's on a stock truck.  Have the fenders been clearanced?

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[79GMC4x4]

I currently have a 79 3/4 Ton 4x4.  It is stock and it also clears 33's.  

[Lt.Del]

Ensure your rear axle ratio can handle that size tire.  If it is a high gear rear, you may want to lower your ratio.  Large tires make a big difference in rear end ratios.
SgtDel

[1976Scottsdale]

Yes, that is true.  I have 3.08 posi's in my 78k10 and that poor thing will barely go up a hill and hold speed with the 33's on it.  3.42 will do fine, 3.73's are better, but 4.10's are... dare I say it, God-like.  Hope gas milage is of no consequence.

[Lt.Del]

I have a 91 sub w/ 33's on her.  The rear is a 3:73, which, with those larger tires,  translates to close to a normal set up 3:08 rear, when you look at the rpm's.

SgtDel  

[DieselTech]

My 78 has 38.5"s on it with 4.88 gears. A little too low sometimes, but with 3.73's it was a total dog. It now gets up to speed like it should, but runs around 3200 Rpm's at about 65 mph. Gas mileage is terrible! Big trucks drink the gas!