A-B1592060-AI SB MODEL 31 VERTOne New Aftermarket Replacement Short Block Fits Briggs & Fits Stratton Model 31 Intek Vertical Shaft Engines This aftermarket replacement short block Fits Briggs & Fits Stratton (B&S) Model 31 Intek vertical shaft small engines. The short block is the core engine assembly including the cylinder block, crankshaft, camshaft, and piston and is used to rebuild or replace a worn or damaged engine bottom end. Designed for vertical shaft configurations