This is a brand new big block Chevy 396-454 belt drive and pulley kit. For use with short style water pumps with up to a 5/8" shaft.

Kit Contents:
 
Aluminum water pump pulley
Aluminum crankshaft pulley Has v groove for water pump.
Steel alternator pulley
1.5'' Cog belt
The cogged 1 1/2" wide "Gilmer" style belt prevents slippage.  
Water pump and crank pulleys are a 1:1 ratio.  Must be used with the factory alternator position, alternator pulley has outside lips to help keep belt aligned.  
Will not work with A/C equipped vehicles with out modification.
Works with mechanical water pumps only (will not work with electric water pumps)