on the drivers side of the engine behind the head on the flat spot between the block and the bellhousing, its on the same plane as the head,,in other words its south of the head LOL..not below it where the freeze plugs are.... is the casting number for all small block chevys. its right under the firewall usually and hard to see....youll need a mirror... its below the oil pressure tap or sender... then go to mortec.com and look up the casting number... that will tell ya the original block...of course not if its bored or crank modified...
just go here
http://www.mortec.com/location.htm mortec
