Can 7 x 20 tires be used for duals on 1930 AA

[GillTownship]

My 1930 Model AA currently has 7 x 20 singles on the back and I would like to put on duals. Is there enough clearance for duals at 7 x 20? If I have to use a narrower 6 x 20 or 6.5 x 20 tire for duals, will those tire sizes fit onto my back rims that currently have a 7 x 20 tire mounted on them? I believe I read in Jim Schild's book that a 7x20 tire does indeed take a different rim size.

[Reds34]

The easiest way to tell would be to take one of the wheels off one side and install it on the opposite side. See how much clearance you have between the tires. I don't think you'll have enough clearance for duals with 7.00. You want to make sure that the tires won't rub whether loaded or not. You should be able to instal 6.00 or 6.50 on those same wheels.

Red

[AndrewD]

I am currently using 700-20 tires mounted on the '31 style wheels on the rear of my '30. There is a little less than 3/4" clearance between the tires, which are BF Goodrich Silvertown's. They don't bulge much when loaded, although I haven't maxed out the weight with these. The truck came with the '31 wheels on the rear, and Delta Hi-Way tires were mounted on them. They just touched with no weight on the back, and didn't bulge with a heavy load. They lasted from the mid 1980's 'till last year, when I had to replace them due to dry rot.
Some of the tire dealers list a cross section width of the tire. I picked the BF Goodrich's because they seemed to be the skinniest. I was going to make up spacers if they rubbed, that may be required if the tires were to be mounted on the 1930 wheels that don't have the thickened center portion.

[GillTownship]

Andrew and Red. Thankyou very much for responding and with the good information that you each provided. That will be helpful to me. If it doesn't look like I can make 7 x 20's work for duals, then I will see if my 2 rims that are currently mounted with the 7 x 20's will accept a 6 x 20 or 6.5 x20 and if that works then I can get by without having to buy extra rims. thankyou again!

[David R.]

Ford specified 6.00-20 all around for duals and 6.00-20 front and 6.50-20 on rear running single.

[Chris Haynes]

When I had 700s on my Early 30 the tires hit the front brake rods when turning.