The Power Adder SBC Short 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. 
Compression Ratio calculated with 65cc cylinder heads

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

Camshaft Kit includes: camshaft, hydraulic roller lifters, roller timing set, thrust plate, lifter dog bones & spring tray--Installed

Power Adder engines carry a 1yr workmanship guarantee.

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

Sealed-Up Kit includes: oil pump, welded pump pick-up, hardened driveshaft, black timing cover & black oil pan--Installed

Torque Converter: 2,000-2,400 Stall w/ Extreme Cam, 2,400-2,600 Stall w/ Eliminator Cam & 2,600-3,000 Stall w/ Mighty Mouse Cam Recommended