The most common methods of increasing horsepower in the Ford 4.6L Modular Motor all have a common thread. Boost. Whether you use turbos, blowers, or nitrous, the bottom end is a mandatory upgrade. The factory connecting rods and hypereutectic cast pistons just arent the ticket for a motor that loves blowers AND rpm. CHP produces a forged rod, forged piston short block for the 4.6L. We use a variety of Probe SRS forged pistons to achieve the correct compression ratio for your application. For the ultimate in performance and reliability Probe 4.6L short blocks are your best alternative. 3.552 to 3.5820 bore - 3.554 stroke Forged steel crankshaft CHP 4340 forged steel connecting rods Probe SRS forged pistons ARP fasteners Iron block Your choice flat top pistons or 4.5cc, 10.5cc, or 18.1cc dish pistons All shortblocks are balanced and blueprinted