Tire size for c20 silverado

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thecantaloupeman

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I have a 1978 c20 Silverado camper special. I wanted to know the proper size tires for it. The door jam said 9.5 but I've heard lots of people say it's supposed to be 8.75. I just got 8.75s but they look a bit too narrow. The rim sticks out a bit. I'm able to exchange the tires for a new size, so am I supposed to be running 9.5s?

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My '78 C20 Burb came stock with 9.50's and I believe it was an option. I know it was the original size because the SPID is still in the glovebox and it still has the original spare tire.
 

75gmck25

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What is the GVW for your truck? Mine K25 has the Camper Special and 8200 GVW packages, which I think required the 9.50 x 16.5 tire package.

For modern tire sizes in 16" you will find that 245/75R16E is a close match in height, and 235/85R16E is a slightly larger diameter. I got rid of my stock split rims and switched to 16" tires because they were easier to find, and in most cases much cheaper than the stock tires.

You should use E (10 ply) load rating if you plan to actually use the weight carrying capacity (mine says 2650 lb camper in the bed). Stock light truck tires don't have the load rating you need.

I've had mine up to about 3200 lbs (full pallet of concrete blocks, also full pallet of bagged cement) without any issues with suspension, tires, etc. I'm sure that two yards of dirt also pushed the load rating.

Bruce
 

thecantaloupeman

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What is the GVW for your truck? Mine K25 has the Camper Special and 8200 GVW packages, which I think required the 9.50 x 16.5 tire package.

For modern tire sizes in 16" you will find that 245/75R16E is a close match in height, and 235/85R16E is a slightly larger diameter. I got rid of my stock split rims and switched to 16" tires because they were easier to find, and in most cases much cheaper than the stock tires.

You should use E (10 ply) load rating if you plan to actually use the weight carrying capacity (mine says 2650 lb camper in the bed). Stock light truck tires don't have the load rating you need.

I've had mine up to about 3200 lbs (full pallet of concrete blocks, also full pallet of bagged cement) without any issues with suspension, tires, etc. I'm sure that two yards of dirt also pushed the load rating.

Bruce
My GVWR is 8200. I spoke to a few people who didn't think think tires were dangerous, and they are only 3/4ths of an inch to narrow. They are 10 ply (E) Firestone Transforce HTs. I'll attach a picturem I'm probably going to go back and exchange for the 9m5s anyway, but will they change the look at all? It looks a bit ugly with the rims sticking out of the tire and I don't know if the 9.5 will change that or not. Thanks.
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bucket

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The 8.75's used the same rims as the 9.50's. I think that's why most of the 70's 16.5 rims had safety beads, much like a 16".
 

Frankenchevy

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Either way, the transforce ht is a great highway tire. I had a set last over 70k.
 

thecantaloupeman

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The 8.75's used the same rims as the 9.50's. I think that's why most of the 70's 16.5 rims had safety beads, much like a 16".
So if this is the case how come the package with 8.75s came with 6 inch rims and the 9.5 package came with 6.75 inch rims? Is it just that they made two different beads to accommodate both tires or something?

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So if this is the case how come the package with 8.75s came with 6 inch rims and the 9.5 package came with 6.75 inch rims? Is it just that they made two different beads to accommodate both tires or something?

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Hmm. I guess I've never seen the 6 inch rims? I thought they were all 6.75.

Either way, if you decide to stick with those tires, it shouldn't cause any issues. Your rims in the picture do have the safety beads to help keep the tire on the bead.
 

thecantaloupeman

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Hmm. I guess I've never seen the 6 inch rims? I thought they were all 6.75.

Either way, if you decide to stick with those tires, it shouldn't cause any issues. Your rims in the picture do have the safety beads to help keep the tire on the bead.
So now that I know it's safe, would it look better with 9.5s? Would it get rid of the extra rim sticking out or would it look the same?

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Here's a pic I still have on my phone. The fronts are the 9.5's on the stock rims.

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idahovette

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You might find someone else to balance those. There are too many weights all together on that rim. Looks like they should have rotated the tire 180 and rebalanced
 

thecantaloupeman

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Here's a pic I still have on my phone. The fronts are the 9.5's on the stock rims.

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I can't see the pic for some reason

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bucket

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You might find someone else to balance those. There are too many weights all together on that rim. Looks like they should have rotated the tire 180 and rebalanced

It looks like they reused old weights too. That's not a big deal I guess, but I can't stand it when they don't match. OCD you could say.

I can't see the pic for some reason

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That's because of Tapatalk unfortunately.
 

thecantaloupeman

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It looks like they reused old weights too. That's not a big deal I guess, but I can't stand it when they don't match. OCD you could say.



That's because of Tapatalk unfortunately.
Oh okay I've just looked at the picture. Do 9.5s have a taller sidewall too? Yours look like they fill more of the wheel well than mine. Mine almost look too small.

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