The wood hauler tires.

These fellas are correct ! Ive played this same game on my Chevy's over the years ! Good luck buddy !!

 

I use this all the time.
http://tire-size-conversion.com/tire-size-comparison/

 

Yep use to use a tire conversion calculator going from the metric to standard size.

But anyway, I think the 235/75/15 was a stock size even on a 4wd truck(at least on half ton)? My k10 I believe the door sticker said 235/75/15 on it. And I too have either a 3.08 or 3.07 rear I forget which?? I thought they made both? Anyway I now have 33/12.50/15 on it and its really too tall of a ratio now. Truck can still get up and move and there great for cruising 60mph but the truck just do sent have the low end it needs cause of the tires. When pulling a big boat up at the lake I always put the T case in 4Lo to get a better ratio.

 

IIRC 235/75/15 uniroyal tiger paws would have been factory equipment along with an overdrive 700r4 if automatic. Sounds like that would put you back to factory specs and regain power/mpg while putting less strain on everything under normal conditions as gm's R&D dept originally intended. Of course there are variables that could come into play.

 

K10s/15s were that size stock bit I think the 3/4 ton were the size pete had if they were not 16" rims.

Id either get the rereads like Dex linked or look for a set of factory takeoffs from newer truck

 

I like to purchase my new rubbers in person. They have a date stamp on them. Everything has a shelf life. One of the national news (cnn) did a story on tires being sold after sitting for years on a shelf. One of the national tire chains was the focus. Rubber deteriorates....

Having said that I run two different sets of 33/12.50 & 13.50 rubbers on 15 in. Rims. They never see the street except for loading on the car hauler.

Btw... Tires are like ( . V . )
Once you play with em' awhile you want a bigger set.

 

The truck has wheels, not rims. MasterMech you of all people should know better!

A 235/75r15 is around 29" tall. The 265/75r15 is about 30.5. Not a ton of difference. I'd probably run a 235 if I had to stick with the 15" wheels. A set of 16" would open up options for truck tires, though I'm not sure how common 6 lug 16" wheels are (I'm talking stock ie.. can get for cheap... stuff)

3.08s are an 80s "fuel crisis" gearing. An 86 1/2 ton should have a 700r4, though GM threw whatever was laying around in their junk in those years, so it could have a TH350 or 400 even.
If it's the O/D trans smaller tires would help to get the revs up a bit and less engine lugging.

 

Pete has a 3/4 ton. I have the 1/2 ton.

My setup is 350/350/205 turning 3.08

 

Pete said it was an 86 1500 which would be a 1/2 ton.

 

And I have never had a problem with tires and I have bought them from everywhere from local shops to discounttirredirect.com never had a tire more than maybe 6 months old. I think this was a rare case of them dumping a warehouse or something?

 

Well your right. I think where I got that then is that it has 3/4ton springs under it.

And if it was 3/4 it would be 16" wheels.

 

I'm watching this thread as I have just acquired a 2000 GMC S15 Sonoma with the ZR2 package. It comes stock with 30/10.50/15. I'm going to need to get new tires and thought about switching also. I'm going to surf CL and see if I can find some good used.

 

The zr2 will look stupid with anything but the 30 or 31's on it. I would get the tires Dex linked too"!!!

 

I think I know what I'm doing but I don't think I would care about looks.

 

Id still get the thread weights. Won't beat that price.