Is it possible? '66 V8 with PS and PB?

Depends on the V-8. If the common "small block" (distributor at rear), yes. If a "big block" (distributor at front), most have to give up power steering and power brakes. Best to get all accessories and pulleys from the same motor. There were many combinations and hard to interchange. You will need the steering center-link from a V-8 car (64-66) and probably a different oil pan or else dent in the one you have appropriately. Stiffer torsion bars would be smart and probably upgrade the brakes.