Need help with tire sizes

[68c-10streetrod]

I've got a 1968 C10 6 lug 2wd fleetside. Looking to lower the rear of the truck, but since the tires and wheels have been changed, I dunno what level of lowering springs to buy. It looks like the front has been lowered already. I know the stock ride height is 32" in front, and 34" in the back. I need to know what size tires this truck came out with, so I can add or deduct the current tire size. I found a spec sheet on the truck, and found these numbers for tires sizes. Front 7.75x15 and rear 17.5x17. I've looked at several tire size websites, but cannot get a comparison between the size of the originals, vs the size of the current. HELP?!?!?!?!

[Pat_Opsahl]

I would also like to know this. I have a completely stock 1967 C10, LWB Fleet, that has 15 inch steel wheels on the front and 16.5 inch on the rear.
I have seen a number of good deals on used 6 lug wheels from 2001 - 2006 suburbans. Will they fit?
Thanks, Patrick in Livermore, CA

[68c-10streetrod]

As long as your truck has the six lug wheel pattern. I'm running 8" wide 255 60 r 15's on mine.

[68c-10streetrod]

Even some of the Toyota truck six lug patterns will fit as well.

[68Stepbed]

The late model wheels will fit, but the backspacing is incorrect and the wheels just don't look right on our classics.

Try giving Coker Tire a call. They specialize in the original bias-ply and nostalgic tires.