I've dynoed at 3 places in town.
Secretservicesauto (near Momentum SW) - mustang dyno - weekdays only
G force (Pearland) - dynojet - weekdays only
Dyno at MSR - dynojet - if they arent racing on weekends, u can possibly dyno there. Check with Richard Z for contact.
You can also call whatever dyno around houston from this list.
http://dynojet.com/dyno_centers/dyno....aspx?state=TX