The Power Adder SBC Short Block comes standard with many features designed to handle high horsepower levels (Turbo, Blower, Nitrous)
The Dual 3/16" Keyway option is highly recommended for supercharger applications.
The ATI Blower Balancer has both the 3 bolt SBC pattern and the standard 2.80" Chrysler Blower Bolt Pattern & extra thick BBC Hub. 
The ATI Balancer requires a matching ATI Timing Cover which accepts a BBC timing cover seal to match the Balancer's larger hub.
Compression Ratio calculated with 65cc cylinder heads

383" Specs:
Block: Smeding Heavy Duty 4 Bolt Mains, 9.025" Deck Height, 1 Piece Seal, 4.000" 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: Forged 2618 High Strength Aluminum, Coated Skirts
Rings: Plasma-Moly Top, Low Friction Oil, 5/64" x 5/64" x 3/16"

406" Specs:
Block: Dart SHP 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: Forged 2618 High Strength Aluminum, Coated Skirts
Rings: Plasma-Moly Top, Low Friction Oil, 1/16" x 1/16" x 3/16"

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

Cam Specs:
Extreme: .510”/.521” Lift, 231°/236° Duration @ .050”, 111 LSA
Eliminator: .544”/.543” Lift, 236°/244° 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: 2,400-2,800 Stall w/ Extreme Cam, 2,600-3,000 Stall w/ Eliminator Cam Required

All of our engine packages are extremely flexible and can be customized! If there is an option you would like and do not see, please call us at 210-446-0960.