Posted by Joe Lorenzino on Tuesday, April 15, 2003 at 1:52AM :
In Reply to: Buying used engine parts posted by Josh on Monday, April 14, 2003 at 3:29PM :
I believe the last of the steel 440 cranks came out in late 71, so any newer will have a cast one. If the oil pan is off, you can tell a steel crank from a cast one by the width of the "parting line": the line where the two halves of the mold meet. On a cast crank, the line is 1/8" or less in width. On a steel crank, it is 3/8" or more wide. The parting line is most visible on the “face” of the crank arms beside the rod bearing journals.
A micrometer set or digital calipers will tell you if things have been, or need to be machined. Most machine shops will stamp their rebuilds, so check on the block for a tag, or numbers such as: m 010, r 020 which would give the bearing undersize in thousandths of an inch. These numbers may also be found on the crank itself, so check the edges and faces of the counterweights. The same for bore sizes; check for tags, or stamped # on the block, or on the top of the pistons themselves. Happy Hunting Joe L.