Technical Recommended rim widths for tires

I'd really like to run 500-18 Firestone ribbed dirt track front tires but the specifications recommend maximum rim width of 5". I notice other tires list a single rim width, some don't mention rim width at all.
Anyone run these on 6" wide rims? Or should I forget about it and go with something else?

Cheers

 

6” would look goofy.

 

^^^^^^
What he said!
Welcome to the HAMB.
By the parameters of this board, no Hot Rod built before 1965
would use a 6 inch rim on front runners IMHO.
What car are you putting 18 inch front dirt track tires on?
We are picture crazy here.
Show what you are building and maybe someone would offer some advice.