I am currently running 255/70/17General Grabbers on my 2004 1500LS. I have access to a brand new set of 245/75/17 Bridgestone Duelers HT tires . tire conversion charts show only about a 1/2" difference in height but in actuality look maybe 3/4 or so taller. Since the Jeep wheels don't match up with my van I was curious to see if anyone was running or had an opinion of the upsizing? just "eyeballing", it it appears there will be enough clearance but not 100% sure. Advice appreciated

current set up -2004 express 1500, 2019 Silverado 255/70/17's & wheels

 

That's a good looking van.

The 255s you're currently running are already taller than the stock 245/70/17 and the 245/75 will add a bit more height. It's enough to change your speedo, odometer MPG calculations etc....

Also remember the clearance only changes by 1/2 the difference in height. That 1/2" difference only means 1/4" clearance change in the wheel well.

This is a good tire size calculator that gives you all the info including how much one tire will change the speedo. https://tiresize.com/calculator/

My 1500 has some rub marks in the wheel well where it rubbed some time in it's past. I'm guessing they overloaded it since it was owned by a utility company and would have kept the stock tire size. The rub marks are limited to the smooth inner well with no evidence of contact on the outer fender or sharp seams. Looks like if they do rub it might not be the end of the world. There would at least be evidence of it without real damage. I can't say what the front would do if it bottomed out with the wheel turned.

 

Thanks no issues at all with the 255/70/17's . Mo only concern was front clearance on shard right or hard left. Other than that it seems I have plenty of room in the wheel well.. Even with the wheels turned all the way to the stops I probably have maybe another 3/4" or so from what I can see on the ground. Are you by chance running the 245/74/17's? Thanks again

 

I'm running the stock 245/70/17.

The issues with rubbing (even with the wheel turned all the way) don't usually show when the van is standing still. The suspension can still compress even with the wheel turned all or most of the way. Turning into a steep driveway for example. Load some weight into the van and it will compress more.

If you want to see what's going to happen under compression, cut the wheel all the way and use a jack to lift it by the control arm.