Hot Rods Wheel and tire size

Hey guys. I have a quick and maybe dumb question. I am putting Firestone bias ply wide whitewalls on my 1957 Chevy truck and I am measuring the wheels and I can't tell if these are 5 inch wide or 5 1/2 inch wide. The rears are def wider than the fronts. I think these are the original wheels that came on the truck. Does anyone know if they were staggered sizes like that and what the size really is? I know it sounds lame but I can't tell if these are 5 inch wide fronts and 5 1/2 rears or 5 1/2 fronts and 6 inch rears. Any thoughts? ANother Hamber is rock this setup...
The Fronts are:
15x6" Wheel Vintiques "Smoothies"
w/ Firestone 6.70-15's

The Rears are:
15x7" Wheel Vintiques "Smoothies"
w/ Firestone 8.90-15's

What would these tire sizes look like on my wheels? Any suggestions? I know it's hard to tell in the photos but the rears are def about 1/2 inch wider than the fronts. Thanks

 

I can't be a lot of help with this question but you don't measure a rim from outside,the 2nd photo is the correct way. HRP

 

Old chevy trucks came with the same wheels front and back. They get replaced as the years go by.

as he said, you measure width inside the flange.

7.50-15 was a common size on those old trucks. Usually a truck tire, which were a bit different from car tires.

 

Like HRP said. Inside inner to outside inner.

 

Here are a few pix for refferance.
The wheels are 6 inch Chevy by 14 inch diameter.
The tires are Giant 9-50-14 Lesters.
Thet are 27 inches in diameter.
The Firestone 8-20-15 will have an even narrower
tread patch than these.
This 9-50 was the widest regular
tire available in the late 50's early 60s.
They were and are still available in 15 inch also.
Jest me but I think wider is better to a point, especially in the rear.
Good luck,
Tony

 

The wheel you're measuring in the first post is 5" wide and the wheels on the truck originally would have all been the same width.

 

Thanks for the response. I still don't know if I should pull the trigger on the 6.70s for the front and what size I should get for the rears.. I guess I will just take a shot and see when they get here.