Corvette Master Cylinder

Hello, can you tell me the difference between your 118-S and 118-L Corvette style master cylinders? I just converted my CJ-7 to 4 wheel disc brakes and now need a 4 wheel disc master cylinder. I'm using a GM style power booster that the master cylinder would attach to and 3/16 brake lines for both front and rear brakes. The front disc are chevy truck style single piston and the rear disc are Willwood 4 piston calibers. Which one of your master cylinders would you recommend? Thank You.