Is a 1990 Buick regal custom front caliper bolts are reverse threaded?

No, the front caliper bolts on a 1990 Buick Regal Custom are not reverse threaded; they are typically standard right-hand threads. When working on brake components, it's important to use the correct tools and torque specifications to avoid damaging the bolts or the caliper. Always consult a repair manual for specific details regarding your vehicle.