K10 Wheels / Tires

[RyanAK]

Hey gang. It’s time to consider wheels and tires for my ‘78 K10 Suburban. Posting here rather than the ‘burb sub-forum because this is applicable to both squarebody trucks and SUVs.

Details - 1978 Silverado K10 Suburban. New crate 350, TH350 with full-time NP203. Stock suspension.



Wheels and tires are up on the list as I go through the driveline/suspension and try to make the truck as smooth and reliable as possible. I’m chasing rattles and vibrations. You know how it goes. But I want to eliminate wheels/tires from the variables as I do that.

The rig currently has stock 15x6 steel wheels and caps and has 235/75R15 Toyo Open Country tires. The tires are 12-1/2 years old. I had them balanced... no help with the vibrations and such. Tread is fine, but I’m not convinced that they’re out of round or have some other issues. So time to replace.

The goal is to make this a reliable family truck. We go up into the state forest quite a bit. And I have a once-a-week 260 mile round-trip that is majority interstate at 70mph+. So an all-around vehicle.

While I really like the look of the stock steel wheels and caps, the 15x6 size really limits tire selection. So I’m trying to decide which direction to go. I’d like a taller tire to get the RPMs down slightly on the highway, plus gain a little bit of clearance and fill up the wheel wells. I’ve considered 15x8 or 16” white wagon-style wheels, but not sure a white wheel will work well with the tan secondary color of the truck. 15x8 WV OEM-style wheels with caps would be good if they’d ever be in stock. Maybe chrome wagons or another aftermarket choice? Mostly leaning to BFG ATs or General Grabbers for rubber. I’m definitely after the best performance for my situation. Looks are obviously a consideration though...

Thanks in advance!

Any and all thoughts appreciated.

[1976gmc20]

Go 16" if you can find them in 6 hole with the correct backspace. That allows you to choose a taller tire with a heavier load rating. Suburbans are heavy and the C range just barely holds them up on pavement.

Maybe 235/85r16 or 245/75r16 D or E range ?

I had a set of those Toyos and they were terrible. Ruined two in short order and the other two wore out quickly. They were a really expensive tire at the time also.

[cadillac_al]

I run 30x9.50 BFG's on my stock wheels on my K10. I have to keep those beautiful hub caps.

[RyanAK]

If I go aftermarket on 6-hole 16”s, any suggestions? I’ve searched high and low without going custom for a wheel I can run the caps on. 16” means an aftermarket wheel. Chrome? Painted? Aluminum?

30x9.50s are a thought. I’d love to keep the caps. Any issues on a 6” rim? Got a pic handy?

[sweetk30]

could do like i did in here for a factory look with stock and aftermarket parts .

http://67-72chevytrucks.com/vboard/s...d.php?t=794636

[1976gmc20]

Originally Posted by RyanAK

If I go aftermarket on 6-hole 16”s, any suggestions? I’ve searched high and low without going custom for a wheel I can run the caps on. 16” means an aftermarket wheel. Chrome? Painted? Aluminum?

30x9.50s are a thought. I’d love to keep the caps. Any issues on a 6” rim? Got a pic handy?

You might have to choose between hubcaps and running a decent tire.

But I shouldn't talk - after my fiasco with the GMT400 wheels, I broke down and just bought a set of 15" steel rallies from a ranch junkyard. At that time I couldn't afford $600++ for new aftermarket wheels shipped in plus new tires. We don't drive the Suburban too much anymore, so the despised LT235/75r15(C)'s have held up okay. Practically new tread still at about ten years old.

I do wonder if a larger/wider tire on 15" wheels would hold up better ????

Theoretically you could run lower pressure and they might be less vulnerable to damage.

I guess it doesn't matter so much if you're always on pavement. Heck, our Suburban had P235/75r15 on it when we got it at 140K miles!

[Old65C10]

Remember the 6 lug pattern is the same pattern used on 2wd and 4x4 Japanese trucks from the 80's on up. I am sure you can find a 16in rim with the correct offset and everything easily. I think that the late 90's to the 2000's 1/2 ton trucks used the 6 lug with 16in tires. I bet there are stock Chevy wheels that will work too.
I have a 3/4 ton Suburban and I am running 16in E load rated tires. I got them off Amazon and they have been great tires. The brand is EcoPath 235/85-16.

[sweetk30]

once gm went ifs suspension the rims got a LOT more backspace = sucked up in more . and the center hub hole went smaller .

so you can not simply just use 88-up gm rims on the solid axle stuff .

[cadillac_al]

I didn't get a chance to get a close up of my tires. I'll get one tomorrow. I would buy another set of BFG 30x9.50's when these wear out. I roll down the interstate from time to time at 70-80 mph. These tires are so smooth on the highway I don't even dare to rotate them

[1976gmc20]

Originally Posted by Old65C10

Remember the 6 lug pattern is the same pattern used on 2wd and 4x4 Japanese trucks from the 80's on up. I am sure you can find a 16in rim with the correct offset and everything easily. I think that the late 90's to the 2000's 1/2 ton trucks used the 6 lug with 16in tires. I bet there are stock Chevy wheels that will work too.

No - no - no - no!

once gm went ifs suspension the rims got a LOT more backspace = sucked up in more . and the center hub hole went smaller .

so you can not simply just use 88-up gm rims on the solid axle stuff .

Yes! I found this out the hard way. The 1988++ wheels will not work even if you cut out the center hole, because the wheel sits too far in and hits the tie rod end. It actually won't even go far enough in on the front to seat on the lugs and rotor, although the bolt circle is exactly the same.

I believe the Toyotas are the same way. I offered to give my "ruined" wheels to the young neighbor for his old T100 but it turns out he already had a set 16" wheels for it that just needed new tires. I'm afraid to use them on my 1989 (which I didn't have back then) because all the weight would be on the lug bolts. The Toyota has a bigger hub.

So anyway I have five junkyard wheels that I can't use and couldn't take back because I had all of them cut out before testing one.

I wish to heck that my Suburban was a 3/4 ton. I would sure like to run LT235/85r16(E).

[RyanAK]

I was ready to give up on the hubcaps for now and go with a 16" rim/tire to get into a better tire choice until cadillac al posted and commented on his GMC... are those 30x9.5s on stock 15x6 rims?

sweetk30... nice work on building up a set of wheels. I like that look. There are D-window wheels available in white for the 6-lug trucks... Why do they all have red and blue pinstripes?

15" 6-lug I have stock 15x8 rally or wagon wheels as options. Or WV for 15x8 steelies with caps, though they're out of stock and I'm unclear on if they're compatible with our front disc brakes.

16" 6-lug is something aftermarket. Not sure what's gonna look right on a truck with a tan secondary color. Still, this is what I'm leaning towards to get into taller/higher-load-rated tire. 265/75R16 BFG ATs or General Grabber A/TXs.

Thoughts on a good looking 16" rim that's sorta 70s appropriate?

[nekkidhillbilly]

wagon wheels are pretty common on tan and brown vehicles in the 70s idk how many bronco I saw with that set up. they also make just steelies that you can run your hubcaps on. lastly late model oem wheels wont fit however aftermarket ones with a deeper offset will so if you found a set off a later chevy like that they should. you could also use a space but idk why you would want new model wheels they pretty ugly.

[nekkidhillbilly]

to give you an idea

[cadillac_al]

Here's a close up of the 30x9.50's. They don't look overly huge for the stock wheels. The middle of the tread isn't wearing out like a tire that's too wide for the rim. Ya gotts love how solid axle trucks wear tires so evenly. Those independent front ends chew up the insides treads of tires.

[dmack91]

Cadillac Al, dang, that is some impressive cracking in the tread. Any idea how old those tires are? My friend has a similar set of bfg's. About 15 years old, lots of tread, but lots of those cracks in between the tread too.

[cadillac_al]

Originally Posted by dmack91

Cadillac Al, dang, that is some impressive cracking in the tread. Any idea how old those tires are? My friend has a similar set of bfg's. About 15 years old, lots of tread, but lots of those cracks in between the tread too.

I would guess at least 20 years old, before they started putting DOT date codes on them. That's the way they looked when I got the truck 8 years ago. I put about 20k miles on them and the tread and cracks haven't changed. The previous owner and I definitely got out money's worth out of them. I have another set of BFG's in storage that I bought in 1998 that don't have a date code on them. If there is a DOT date code it is well hidden on BFG's.

[RyanAK]

Thanks for the photos, Al. That’s impressive longevity on those BFGs. Be safe, brother.

Nekkid- thanks for the photo. The Suburban original paint is actually dark red/maroon that has faded to a sorta russet color. I actually like the faded paint better than the red. That Bronco looks great with the wagon wheels. You see most of our trucks with white as the secondary color it was hard to picture white wheels with the tan belt.

I’m on the road for work this week and decided to roll the dice on bringing the 41 year old rig 150 miles from home. Working through some vibrations at 45-55mph and 65-70mph, but other than that, it did well. Definitely need to get tires sorted out.

Here’s a couple photos.

[1976gmc20]

You could always just kick the can down the road and get a new set of LT235/75r15(C) on the stock wheels.

If you're all or mostly on pavement you likely won't have the tire damage. We didn't have any trouble with the tires on our Suburban the first couple years until we moved out here ten miles off the highway on gravel/dirt road. Then we started getting flats all the time it seemed and many of them not repairable.

Our Suburban apparently ran on P235/75r15(B) tires for 140K miles before we got it. I swapped them out for LT(C)'s pretty soon and I think I still have the factory spare sitting out there in the shed

Of course our Suburban has the 700r4 with overdrive so highway speed rpms aren't so much of an issue. But 70++ does kill the mileage down to 12 or 13, but at 65 it gets (or used to, anyway) 15-16. We drive it so little these days that even when I take it to town on the highway I just leave it in Drive. The extra rpms are probably good for the engine once in a while.

[RyanAK]

Still considering what 16" wheel to run. I think wagon wheels for now, and a 32" tire. What's with the blue and red stripes on aftermarket wagons? I don't thing the OEM 'styled' wheels had the pin-striping...?

[TwoFiftyShifter]

If you like the skinny look, you can go 235/85R16. They are almost 32 inches, just like a 265/75R16.

[RyanAK]

I've definitely considered 235s. Not sure which way I'll go, but right now I'm leaning 265/75. I do like the tall/skinny look on OE style wheels with hub caps.

R

[sweetk30]

here is 255/85/16 on my k30 all stock rims / caps has around 3" lift also . there a 33" tire .

[RyanAK]

If I had eight lugs... I'd be set. More of a challenge for six-hole to get a nice stance without a lift... and 15x6 is the real limitation for getting a decent tire.

That K30 looks great. A real truck.

[1976gmc20]

Someone once suggested to me that I just swap in 3/4 ton 8 bolt axles front and rear, since the rest of the Suburban is essentially the same.

If mine were still more of a primary vehicle for us, I might just do that. But I figured that there would be a whole lot more "little stuff" to deal with that would drive me crazy, other than the obvious u-bolts or spring shackles (might as well upgrade springs also). I'm sure the u-joints wouldn't match up and I have no idea about brake line fittings to the axles.

[RyanAK]

16x8 Cragar Nomad 8-spoke wagon wheels will be here Tuesday. Any final thoughts on size or brand/model on a stock Suburban before I order tires? Leaning 265/75R16 ATs in either General Grabber A/TX, BFG All-Terrain TA KO2, or Firestone Destination A/T. Forest road-capable with quiet and comfortable highway manners. Appreciate all the thoughts.