K20 Wheel/Tire Confirmation

[iflyfisher]

Hi Folks,

I am getting my Dad's '73 K20 Custom back on road. I'll be doing some restoration, but I would also like to drive the truck while working on it. The old Sears tires are heavily cracked. I can't even imagine how old they are. The truck was last registered in 2005. The tires are 9.5 - 16.5. The outside diameter is around 29". I'm hoping I can find a set of rims and tires used that can get me on the road. I've been looking through this forum and looks like I can use a 16" to 17" wheel with a 8x6.5 bolt pattern and a center bore of 5". Some have suggested the max tire diameter of around 31-32". I presume that would be okay with a 10" width. Looking at my wheel wells and current tires, up to a 255/75 R17 or a 265/75 R16 look like they should work. Do I need to worry about offset and depth of bolt hole or can I simply look for wheels and tires with these specs? I don't want to spend a lot of money right now as I may change my mind regarding wheels once the truck has been updated.

Thanks in advance!

Ken

 

[Strick]

Trying to find some 16.5's that aren't 36+ is going to be difficult. I'd keep an eye out for some 16's & 265-285 range tires. They'll probably be 20 years newer than any 16.5's as well. Happy hunting.

HS

 

[Craig 85]

Firestone still makes a 9.50-16.5" tire. About $199 each on amazon, but it basically a highway tread. I attached a link. My K30 had 265/75R 16's on when I got it with no rubbing issues. The GM PY0 wheels are 16x6.5". The have a little more back spacing that the 16" steel wheels these trucks came with.

https://www.amazon.com/dp/B002C82FZQ/

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[75gmck25]

I also had similar tires and wheels on my ‘75.

I found the cheapest solution for wheels was to go to pick and pull and get 8 bolt 16” steel wheels off a 3/ 4 ton GMC or Chevy. I paid $25 each for one I pulled myself.

For tires I just looked for the best price on 245/75R16E tires with a decent looking tread pattern. They are similar in height to your original 9.50-16.5 tires, and they are a common size for truck tires. You can even find them at Walmart.

In general, your truck can probably handle up to about 285/75R16 without any fender trimming. However, you might then want to also use a wider wheel.

I bought load range E (10 ply equivalent) tires so I could keep the full load rating on my truck. You could also use C load range tires, which are common on half tons, but they don’t have the right rating for heavy loads.

 

[iflyfisher]

Thanks Strick, Craig, and 75GMCK25. A local guy has a set of aluminum 16s with 265/75’s Ling Long ATs that have about 50% life remaining. Not a fan of the tires. The wheels are okay. But, they would be temporary, and I can probably get them for a few hundred. They would get me on the road.

 

[Travlr]

Thanks Strick, Craig, and 75GMCK25. A local guy has a set of aluminum 16s with 265/75’s Ling Long ATs that have about 50% life remaining. Not a fan of the tires. The wheels are okay. But, they would be temporary, and I can probably get them for a few hundred. They would get me on the road.

If I remember right any eight lug Chevy up thru 2004 (?) has rims that will fit any square body eight lug truck. I scored some aftermarket rims (and tires) that probably cost quite a bit more new than I paid for them. Takeoffs when a guy wanted something else. I'll need tires pretty soon after getting it on the road but the rims are here to stay. Unless you have money to burn, I'd be looking for something I could live with long term and not spend money on something to be replaced.

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[bucket]

Hi Folks,

I am getting my Dad's '73 K20 Custom back on road. I'll be doing some restoration, but I would also like to drive the truck while working on it. The old Sears tires are heavily cracked. I can't even imagine how old they are. The truck was last registered in 2005. The tires are 9.5 - 16.5. The outside diameter is around 29". I'm hoping I can find a set of rims and tires used that can get me on the road. I've been looking through this forum and looks like I can use a 16" to 17" wheel with a 8x6.5 bolt pattern and a center bore of 5". Some have suggested the max tire diameter of around 31-32". I presume that would be okay with a 10" width. Looking at my wheel wells and current tires, up to a 255/75 R17 or a 265/75 R16 look like they should work. Do I need to worry about offset and depth of bolt hole or can I simply look for wheels and tires with these specs? I don't want to spend a lot of money right now as I may change my mind regarding wheels once the truck has been updated.

Thanks in advance!

Ken

Whatever you do, don't pitch or scrap those rims. Those rims pictured are not the standard rims, they are the optional 9.75" wide rims. The resto folks love them. If you want the period correct look, you can still get beefy bias ply tires for them.

STA Super Traxion® I Light Truck Tires I Specialty Tires of America

Bias Ply Light Truck and Equipment Tires

www.stausaonline.com

STA Trailbreaker® I Light Truck Tires I Specialty Tires of America

For 4×4 On and Off-Road Performance | SPECIAL ORDER – Call for Availability Features and Benefits:

www.stausaonline.com

 

[bucket]

Also, the 12.00x16.5" size is proper for those. The 9.50x16.5" size is meant for a 16.5x6.75" rim.

 

[iflyfisher]

@Travir, I was hoping to avoid dropping $2-$3K on wheels and tires before the truck has been restored as I'm not sure what I want now, which also may be different than what I'd want after the truck has been restored. So the thought was getting something cheap but workable for the time being.

@bucket, great reply! I didn't think there was a chance at getting good tires to fit the existing wheels. Thanks! Also appreciate the tip regarding the correct tire width. Thinking now that maybe I should have the wheels blasted and powdercoated white. Hmmmm.......

 

[1x1_Speed_Craig]

It sounds like you may already be set, but I thought I'd mention that I have H2 wheels with Nitto 255-80R/17s on my '86 M1008 (K30). The H2 wheels have a lot of backspacing, which caused drag link joint clearance issues with the wider tires that were on the truck when I got it (at full lock to the right, the tire hit the joint and ripped the grease boot).

With the new tires, clearance is good.

 

[iflyfisher]

Thanks @1x1_Speed_Craig. You have me wondering more about what size tire I can work with. If I were to go 12x16.5 as @bucket notes these wheels were designed for, that extra width may cut into my clearance. Does anyone know if 32” will clear with 12” tires? I have found a few 33” options, but those are likely a non starter I presume. I suppose I could put a 2” lift on the truck, which I am not opposed to. Seems like a lot of tire for my little 350.

 

[Craig 85]

I found these pictures on another forum. The link is below the pictures. Supposedly it has 9.75x16.5” wheels with 12-16.5 tires. You can tell from the pictures the front leaves still have somewhat of a negative arc. So it’s either a 2 or 3 leaf front pack. I’d guess 3. I can’t tell if the fenders are trimmed or not. If they are it’s minimal.

A 2” lift would probably make the truck ride better than the 50 year old springs on it. Tuff Country EZ Rides are a great spring. I’ve used them on my last two trucks.

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http://www.67-72chevytrucks.com/vboard/showthread.php?t=571804

 

[bucket]

Thanks @1x1_Speed_Craig. You have me wondering more about what size tire I can work with. If I were to go 12x16.5 as @bucket notes these wheels were designed for, that extra width may cut into my clearance. Does anyone know if 32” will clear with 12” tires? I have found a few 33” options, but those are likely a non starter I presume. I suppose I could put a 2” lift on the truck, which I am not opposed to. Seems like a lot of tire for my little 350.

I ran that wheel and tire size on my 2wd C20, I can only assume it would also fit a 4x4 without clearance issues.

 

[iflyfisher]

@Craig 85 - thanks for the pics and info regarding the lift. I’ll probably end up doing the lift. I have a Sierra 1500 AT4 that has a 2” lift and really like it.

@bucket - not quite sure what you are confirming. I’m guessing the question regarding a 32” diameter and 12” width, not the 33” diameter. As much as I like the idea of powder coating these old 16.5’s, I am growing more hesitant due to the lack of 32” or smaller tire options. I have spent a lot of time searching the internet and have not found a single all terrain 12 / 16.5 that is 32” or under. Both the two you noted above were over 32” for the 12” width. So I may end up bailing on the 16.5’s and selling them to someone who can manage the larger diameter tires.

Thanks again gents!

 

[bucket]

@Craig 85 - thanks for the pics and info regarding the lift. I’ll probably end up doing the lift. I have a Sierra 1500 AT4 that has a 2” lift and really like it.

@bucket - not quite sure what you are confirming. I’m guessing the question regarding a 32” diameter and 12” width, not the 33” diameter. As much as I like the idea of powder coating these old 16.5’s, I am growing more hesitant due to the lack of 32” or smaller tire options. I have spent a lot of time searching the internet and have not found a single all terrain 12 / 16.5 that is 32” or under. Both the two you noted above were over 32” for the 12” width. So I may end up bailing on the 16.5’s and selling them to someone who can manage the larger diameter tires.

Thanks again gents!

The old tire sizing is funny. The 12.00x16.5 isn't very tall, they tend to be a little shorter than your average modern 33x12.5 tire, at least the ones I have. The biggest issue is whether or not you can deal with a bias ply tire instead of a modern radial. They have their downsides (of varying degrees, just depends on the specific tire model) but have their upsides as well.

Also, I was only confirming that they should fit and clear the fenders fine. My C20 rides a little lower than the 4x4 trucks, and they fit mine.