I use a guy in Muncie Indiana and have used one outside of Toledo Ohio
Nyes Automotive in Muncie does good work
APD in Ohio is good
Level Perfromance in Femont ohio is also good
Nye's dyno made 960hp and ran 4.6's in my car, APD dyno made 971 and ran 4.8's, thats why I always dont trust the dyno #'s
If you want more info of any them places let me know.