Check out locations for the Hunter GSP 9700 Road Force Balance Machine:
http://www.gsp9700.com/pub/search/FindLocations.cfm
I have oversize tires on my SUV (Bridgestone Revo's on 17" Cobra "R" rims) that are huge and heavy. Having them road force balanced (with stick-on weights on the inside only) made a world of difference. No shake or shimmy up into triple digits.
Pulled the PSE FIA wheels and BFG's off my ERA, and was going to take them in, until I saw that I only had 3/4 oz. weight on the worst one. No noticeable vibrations, so I decided to leave well enough alone, and did not have them re-balanced.
regards,
Jeff