You can find 285/85R15 black walls many places for about $75 each. This is a close match to the original tire size.
I think you need to double-check that size, 285mm is over 11 inches wide (compared to ~7-1/4 inches for a 7.00x15 tire). A 7 inch wide tire would be around 185 mm. I run LT265/75R16's on my F250 and they're definitely not pizza cutters. They'd look almost comical on an AD.
To the OP, Go to TireRack.com and browse the sizes available, If you look at the specs for a tire, it will tell you the diameter and overall width. Here's the specs for a 700-15: Diameter 29.18 Tread Width 5.38 Overall Width 7.35 Revolutions per mile 691.
Here's their listing of all
15 inch tires.
