wheel/tire specs help needed

[68c10owner]

Hi guys. Long time member but new to this body style. Picking up a 2000 GMC 1500 2wd extended cab that the previous owner lowered. Im guesing its a 4/6. It still has the stock wheels and tires. Im looking for low cost wheel upgrades. I noticed later model OEM wheels is a popular option and some look great but what specs do I need to look at? I know its a 6x5.5 bolt pattern but thats all I know. Looking at 20" wheels, how wide can I go? What backspacing? And what tire size will fit front and rear? Not looking to go much shorter than a 45 series sidewall. Thanks for the input

[Palf70Step]

Most of the factory rims are 7" wide. I think the 18s or 20s are 8". Figure your current tire combo, height then calculate a tire combo on the other rims that have the same height and you should probably clear OK.

Such as I am guessing you have either 235/75x16 or 255/70x16 which is a hair over 30" tall.
On an 18 inch rim a 255/60 ro 265/60 would keep you in the hair above 30" tall combo.
ON a 20" rim a 255/50 or 265/50 tire would keep you in that range. I do not know of hand what was the factory size tires on the newer 18" or 20" wheels.

I had some Nissan 17"x 7.5" alloy rims on a couple my trucks. They fit well and I was running a 265/65x17 tire which kept it in the same height range.

[68c10owner]

Originally Posted by Palf70Step

Most of the factory rims are 7" wide. I think the 18s or 20s are 8". Figure your current tire combo, height then calculate a tire combo on the other rims that have the same height and you should probably clear OK.

Such as I am guessing you have either 235/75x16 or 255/70x16 which is a hair over 30" tall.
On an 18 inch rim a 255/60 ro 265/60 would keep you in the hair above 30" tall combo.
ON a 20" rim a 255/50 or 265/50 tire would keep you in that range. I do not know of hand what was the factory size tires on the newer 18" or 20" wheels.

I had some Nissan 17"x 7.5" alloy rims on a couple my trucks. They fit well and I was running a 265/65x17 tire which kept it in the same height range.

Thanks. Didnt even bother to look at the stock size. Its still at my friend's house so I'll check next time I'm over there. I can figure out the height easy enough but I was more worried about getting the correct width and backspacing.

[Palf70Step]

If you are using stock style rims, you shouldn't have any issues with BS and width.

The white aftermarket wheels (16x8 with 265/70) I had on my 02 I loved, but not sure they would work on a lowered truck.

[68c10owner]

Originally Posted by Palf70Step

If you are using stock style rims, you shouldn't have any issues with BS and width.

That actually makes perfect sense and didnt think about that. But I'm not sure if I'm going to use OEM or aftermarket yet. Wheel selection in 6 lug for my taste is pretty limited.

[Palf70Step]

I know full sized Nissan trucks/SUVs work on GM trucks. Not sure about Toyota or Ferd 6 lug. Biggest thing would probably be the bore size. The Nissan is just big enough, but I think the Toyota might be a little smaller. Just not sure.

I didn't have lowered trucks (too many crappy roads and trails where I drive), but the one thing I didn't care for one the GM 16 and 17" wheels as they were only 7" wide and I wanted a bit more width. I found the Nissan Titan/Armada rims by chance and like them for stock style.