wheels and tires


anybody out there do any extensive wheel and tire experimentation on their rig? I have an 86 c-20 that I'm messing with,its got the stock 6.5x16 wheels and 235 85r tires,I know its alot towards personal preference but I'm more interested in things like turnining radius,added weight on front suspension parts with bigger tires and the obvious how good the tire is on and off road and getting around in the snow,I also dont want to lift it unless i absolutely have too.I also hear alot about frame cracks at the steering box,does moving up too bigger wheels and tires maybe cause this problem?,or is it a design problem with how the steering box is mounted on the frame?I'll take any feedback,thanks
The problem with stock chevys is that the wheel base on our trucks stock is too short, You will notice a huge difference in handling if you go to a 10" or 12" wide rim, I put a 15X10 rim with a 235/70/15 tire on my 78 c20 and it was a world of a differance in handling. Hope this helps.


Senior Member
Lafayette, LA
Steering box cracks come with abuse and oversized tires. I am about to swap to 33's and plan on definately getting a steering brace. They are avalible through many people including JCWhittney. Check out chucks site http://www.chuckschevytruckpages.com
he has links all over to get this brace. a few basic lift principles
33's fit with 2.5inches or even NO lift depending on the truck(maybe some minor trimming)
35's will fit under a 4inch usually minor trimming under full flex.
long wheelbase chevy's all have a huge turning radius. I agree with blzn74 on wider rims my 15x10's greatly improved my turning radius not to mention I am in a blazer the shortest of the GM wheelbases


PlowSite.com Addict
For your 2wd, the steering box brace probably isn't really necessary but it can't hurt - of course, I am the nutcase that's double-framing a 1-ton.................................... :D

Snow and mud are kind of at opposite ends of the scale, meaning a tire that does well on one isn't really the best choice for the other. For mud, a wide tire for extra "flotation" is ideal while in snow, narrow with lots of "bite" is preferred.

The steering box area frame cracks are, as 85w/350 points out, generally a result of stressing the area beyond what it was designed for. As far as I know, 1/2 and 3/4 ton frames are pretty much identical while 1-tons are a little beefier. I know I've never had any problems with the stock setup on my '75, which came from the factory as a C-35 SRW pickup. Among the many things I've altered on it, I put a 2" body lift on when I swapped cabs about 10 years ago.

That 2" lift was easy to do and all my linkages/wires/etc were able to be left "stock". There was just enough adjustment on the transmission shift linkage, and the steering shaft was long enough after I removed the 2 plastic rivets. 2" of lift isn't that noticeable at a glance but it does make a difference, also makes working under the truck easier. Any more lift than that and you start getting into extra work extending linkages etc. Not a problem, just something to be aware of.

Chuck Smith

2000 Club Member
Couple of things about tires. Just because a tires says "33 whatever" on the sidewall, doesn't mean it measures 33" tall. My first set of 33's measured 30" with a tape measure. They were Dunlop all terrains of some sort. (It was 12 years ago, and I had them for a month.) The problem was that I installed a 4" suspension lift before the tires, and the Dunlops looked puny (which they were). Around here, at the time, we built trucks for wheeling more than looks. With a 33" tire and a 4" suspension lift, you could get full suspension travel, and over extension/ over compression. Lots of axle articulation in the ruts where we wheeled (some of the ruts were left by 44's). Tires rubbing was not a problem. I constantly see trucks with tires on them that "fit", but there is no way the suspension can fully compress. The tires will rub, up front, the edge of the fender will slice the tire crown (where the sidewall meets the tread) to death. I sold the Dunlops and got 35" BFG Mud T/A's. They measured 35" with a tape measure. I had to trim the front fenders just a little to allow full suspension travel in all steering positions. I then added a 3" body lift, and moved up to 36" Swampers. They too measure 36" with a tape measure. If you look in the 4wd mags, the tires ads often list "O.D." of tires in their size charts.

I will say that the BFG's with the soft sidewall give an excellent ride. They were a big improvement. Although soft, they are 3 ply sidewalls, most tires are 2 ply sidewall.

As far as turning radius, I don't know that wider tires help, but I do know if you install a new 4" drop steering arm with a 4" suspension lift kit(which is a must with a 4" lift), your turning radius will be tighter than factory, that's for sure.

cj if your truck is 2wd, then you don't really have to worry about a mud tire, since you most likely won't be in deep mud. My brother is very happy with the BFG AT. I forget the size offhand, but it is about 9" wide, and 31" tall. Does great plowing, on the boat ramp, and in normal offroad conditions. He has them on a Dodge Ram 1500 4wd.

I get the impression your truck might be 4wd, since you mention lifting it, and the frame brace. The frame brace is not offered for the 2wd, or I don't know anyone who has added one to a 2wd. And lifting a 2wd, the only real option is a body lift.

GM added a brace to the frame on later models, I believe 84& up, but I am unsure. The GM brace, is just a brace. The kits sold by JC Whitney and others come with the brace, and a plate to reinforce and/or repair cracks. The GM brace is supposed to stop cracks, the plate and brace will do a better job of prevnting cracks.

I have had a lift kit and 35" or bigger tires on my 77 for 13 years now, and no cracks in the frame. In those 13 years there have been times the front tires have been a lot higher off the ground than I would like to know. I have replaced, tie rod ends, drag links, u joints, 2 steering stabilizers, and one center link on the front end. No steering box problems. Now IF I was going to run 44's on my truck, I'd be concerned about the frame cracking around the steering box....


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