If you have drum brakes in the rear then you need a residual pressure valve. This keeps the cylinder piston out against the shoes, so they start moving the shoes upon application of the master movement. You also may want to put a 2 lbs valve on the front. There might already be a residual valve in the rear feed line. It is located under the seat for the brake line in the master. That would be factory. Make sure if it has one that it's working.
The best setup for the front is Granada 11" rotors with the GM metric calipers. They can be drilled with Chevy pattern. You may have them on the S10. The 9 inch are on the small swept area for that application.
Contact
tech@powerbyace.com for part numbers and suppliers. They no longer make the brackets. However know who has the better ones.