Tires / Wheels advice needed

[Heavy Metal Doctor]

I wanted to do a work truck type of build and ordered a set of these Topcad tires:
http://www.rpphobby.com/product_p/top15429.htm

Then, I just bought a set of these stamped steel bead-lock wheel form RC4WD
http://store.rc4wd.com/Diesel-Rear-S...-2_p_1847.html

Does anyone have any experience with which tires work well with the beadlocks or how to make them work with the Topcads? I tried putting the ring inside a tire, then putting the wheel halves in to start the screws and it just seemed to be way too tight of a fit. The problem is, it seems like the inner ring leaves very little space for the bead of the tire -- like you can't tighten the screws enough to draw the halves together......I'm half tempted to measure it out and then mill down the inner rings 'till it fits right, but hoped maybe someone has some simpler advice.