I did a lot of research and really liked the crossfire system. Better than the similar cat's eye me thinks.
Sadly, I couldn't find a way to mount them nicely with my rear wheel simulators (225/75 R16). Just too tight and nothing sturdy to mount to.....and I couldn't justify completely cutting to expose the center hub bolts.
I think this would be the way to go if you had larger wheels, or did not have the simulators
I ended up going with rigid extenders, found on ebay. Mine needed 5-1/2 inc long extentions
and the only way IMO to make them work, is to support with rubber flange type supports
Dually Valves - Stabilizers
in fact, this is a good source for extensions of all shapes and sizes....
and they also sell long valves that you could get your tire shop to install (no extension reqd).
Mine came with braided extensions from the factory. I fought leaks big time with them. and the support clips with them were junk too