Tire Size question

[Tommyd11730]

Hey Guys new 84 K2500 owner here (on the slow boat heading my way as I type this).  The truck has steels and 235\85\16 tires on it.  I was wondering, whats the largest tire that is generally used with these rims?  I know thats a loaded question and I would rather er on the safe side. By that I mean to say it's generally accepted 31x10.5x15s fit a K5, and they did mine just perfect.

Looking at the photos below the 235s just look small.

Thanks Guys!

[K20Detroit]

I have 285/75/16 tires on my '84 K20 diesel with HD suspension option.
They are on the 07 era Duramax alloy rims with a more sunk in offset, same width.
They fit and look great, however sharp right turns causes the drag link to rub a bit.
OEM wheels wouldn't have that issue.
I would prefer 255/85/16 tires, though they're hard to get replacements for locally.
Both are 33" tall.

[LTZ C20]

Welcome from California. I run 265/75R16's on my 2500. The tires on mine look like they fit nicely. Your truck looks great, tires look like they fit perfectly. That's a good tire size for a 2500. Mine is a Camper Special and I have 2500/3500 aluminum alloy wheels. What are most commonly referred to as Duramax wheels, like K20Detroit.

Are they Michelin or BFG's? I have BFG Commercial T/A's. I don't have any rubbing issues. What other info do you have on the truck?

Mine.

[Irish_Alley]

generally rims aint the problem but its the amount of lift it has
http://forum.73-87chevytrucks.com/smforum/index.php?topic=31301.0

im running 285/75/16 equate to 32.8" but should be around 32.
http://forum.73-87chevytrucks.com/smforum/index.php?topic=31591.msg265311#msg265311

[K20Detroit]

Completely forgot a picture. Old, but it's on the 285's;


Mine is a wheel offset issue, for sure. If the wheels were out another 1/4 or more, like stock wheels, it wouldn't hit the drag link/rod end.
My 285's are closer to 33" tall. The extra diameter really helps my diesel at 65-75mph, even with my 700R4.
If 255/85/16's were more common, I would go with them for sure. I may go with them next anyways. They give you the ~33" height, without the 285 width friction.

[LTZ C20]

285 is alot of tire also, you could go with 265, it's still a lot of tread. I have 265's and don't rub a single thing, the offset isn't an issue either, I have full lock to lock ability and it's all completely stock suspension and steering components.

[Tommyd11730]

Hmmmm  so the 255/85/16s will fit the 84 factory GM rims (I got plain Janes with poverty caps).  Thanks!

[hatzie]

Hmmmm  so the 255/85/16s will fit the 84 factory GM rims (I got plain Janes with poverty caps).  Thanks!

Not a problem to fit 33's.  255/85/16 and 285/75/16 are both 33" tires.  They will both fit on steel 8 lug 16" wheels. 

BTW you can take your pick of 3/4 & 1 ton 16" 8 lug GM light truck wheels through 2010 when GM changed the bolt circle to a metric diameter.  You can get outside threaded lugs with SAE internal threads to fit the center caps that came with the later wheels.

[LTZ C20]

Hmmmm  so the 255/85/16s will fit the 84 factory GM rims (I got plain Janes with poverty caps).  Thanks!

Not a problem to fit 33's.  255/85/16 and 285/75/16 are both 33" tires.  They will both fit on steel 8 lug 16" wheels. 

BTW you can take your pick of 3/4 & 1 ton 16" 8 lug GM light truck wheels through 2010 when GM changed the bolt circle to a metric diameter.  You can get outside threaded lugs with SAE internal threads to fit the center caps that came with the later wheels.

Yes this. That's how I was able to fit 08 GM aluminum wheels on my truck with 265/75/16 tires. I just put my BFG's on the 08 GM wheels and bought a new set of lug nuts with the square body wheel stud thread. Everything fit perfectly and easily. I know have the same set of wheels and tires on my 02 2500 HD. The truck in reply #3 is mine obviously.

[Tommyd11730]

Man, you guys are good!  I have to tell you though, I kinda am partial to my factory 16s with the dog dishes.

A thought did occur to me.  Did GM put 17s with 8 lugs on any trucks that would fit my 84?  Here is the rub, the 33s  would cost a bundle for 4 tires.  I can get 17s at a very affordable price.  So it got me to wondering,  4 17" take off rims would be a heck of a lot cheaper then 4 33s.
Thanks!

[zieg85]

Man, you guys are good!  I have to tell you though, I kinda am partial to my factory 16s with the dog dishes.

A thought did occur to me.  Did GM put 17s with 8 lugs on any trucks that would fit my 84?  Here is the rub, the 33s  would cost a bundle for 4 tires.  I can get 17s at a very affordable price.  So it got me to wondering,  4 17" take off rims would be a heck of a lot cheaper then 4 33s.
Thanks!

While I personally don't like this style or the steel rim offered on GM trucks in 17" here is one that fits our lug nut pattern.  GM changed the 8 lug pattern with the 2011 model year

[Tommyd11730]

Your right that is butt ugly!

[hatzie]

Man, you guys are good!  I have to tell you though, I kinda am partial to my factory 16s with the dog dishes.

GM stopped using the lumpy center wheels for the dog dish caps in 1990 or 1991.

You can get away with later model Ford Econoline van 16x7 8lug x 6.5 lug wheels even tho they are 1/2" wider.  Make sure they have ACCURIDE stamped on em.

You could use the 1988-2001 GM T400 16x6.5 8lug x 6.5 gray steel wheels with the stainless beauty rings.  To use the 1988-2010 style center caps you need 32 Dual External Thread 9/16-18 lug nuts for the plastic thread on retainers.  You can find sets of 24 & 32 on Evilbay.  I think they'd look good in white.

[LTZ C20]

Man, you guys are good!  I have to tell you though, I kinda am partial to my factory 16s with the dog dishes.

A thought did occur to me.  Did GM put 17s with 8 lugs on any trucks that would fit my 84?  Here is the rub, the 33s  would cost a bundle for 4 tires.  I can get 17s at a very affordable price.  So it got me to wondering,  4 17" take off rims would be a heck of a lot cheaper then 4 33s.
Thanks!

While I personally don't like this style or the steel rim offered on GM trucks in 17" here is one that fits our lug nut pattern.  GM changed the 8 lug pattern with the 2011 model year

GMC had an 8 lug set that are 17 inch that don't look to bad and you could put Chevy center caps on. My girlfriend's dad had them on his 08 GMC 3500 diesel. Let me see if I can find a picture.

[LTZ C20]

Found it. I believe it's the same dimensions as the style Zieg showed in reply #11 but these are a different design and are 17s. Also, you can put Chevy center caps on.