is a superswamper irok radial in a 36x13.50R20 a true 36" tire or does it run small? and the baja claw radials in a 36", are they a true 36" tire or do they run small as well? if they do, would it justify just going with a 35" tire for a 20" wheel?

 

it will either be a true 36 or a 35.8" most mfr's list the full specs of their tires on their webpages... do you have a lift on your truck? 36's aren't gonna roll without 6-8"

 

Most tire manufacturers round tire sizes up to the next whole number. You can find the exact height and width on the manufacturers website like BalogUK said.

 

iam up 9"s