The Power Adder SBC Long Block comes standard with many features designed to handle high horsepower levels (Turbo, Blower, Nitrous)
The Dual Keyway option is highly recommended for supercharger applications.
The Blower Balancer has both the 3 bolt SBC pattern and the standard 2.80" Chrysler Blower Bolt Pattern & extra thick BBC Hub. 

406" Specs:
Block: Smeding Heavy Duty 4 Bolt Mains, 9.025" Deck Height, 1 Piece Seal, 4.125" Bore
Crankshaft: Smeding 4340 Forged Steel, Internal/External Balance, 3.800" Stroke
Rods: Smeding 4340 Forged Steel H-Beam with 7/16" Bolts, 5.700" Length
Pistons: JE Forged 2618 High Strength Aluminum, Coated Skirts
Rings: Stainless Steel Top, Napier 2nd, Low Friction Oil, 1.2/1.2/3.0
Rocker Arms: Smeding 1.5 Ratio, Full-Roller
Cylinder Heads: Smeding Aluminum, 210cc Intake Port, 2.08”/1.60” Valves, 65cc Chambers
Head Gaskets: Cometic Multi-Layer-Steel
Head Fasteners: ARP Head Fastener Kit

Cam Specs:
Extreme: .510”/.521” Lift, 231°/236° Duration @ .050”, 111 LSA
Eliminator: .544”/.543” Lift, 236°/244° Duration @ .050”, 110 LSA
Mighty Mouse: .549”/.546” Lift, 242°/250° Duration @ .050”, 110 LSA

Torque Converter: 2,400-2,600 Stall w/ Extreme Cam, 2,600-3,000 Stall w/ Eliminator Cam Required

Power Adder engines carry a 1yr workmanship guarantee.