We run the Hoosier Fks now and I want to run the A40s.
The rights on the FKs are 11x9x6
The rights on the A40 are 11x8x6
mounting on a 10 inch rim
Question any disadvantage from the one inch diff from 11x9 to 11x8
Its not a big deal, you mount them on 10" wheels and stretch them to whatever size you need them. Some air and heat saves you from buying more wheels you don't need.
Keep in mind that the two tires have considerably different sidewall construction.
The A40 isn't worth a plug nickel until it gets heat in it (difficult to do in a non-prep class, btw.)
The advantage of a narrower right side wheel might be to gain some sidebite (especially if this is for K3.)
I've got some freshly refinished used A40s here in the shop, but I can guarantee they've all had prep in them at one time or another.