Note: When using a stock OEM valley pan on an engine running a Hyd. or Solid Roller camshaft, be sure to clearance the underside of the valley pan so it will clear the link bars on the roller lifters. The easiest way to do this is with a ball-peen hammer, 1972 and prior valley pans only need to be clearanced on the Passenger side right below the PCV valve back to about the middle of the engine while 1973 and up valley pans require clearancing on both sides.
The best way to check for clearance is to set the valley pan in place prior to installing the cylinder heads on the shortblock, with the lifters installed rotate the crank/cam to check for any contact, .100" is a safe clearance to shoot for. Please contact us if you need more info.