used timing chain?

Don't do it. A tensioner will keep the chain tight but it doesn't make up for wear. The chain design and gears are designed to work together. Inexpensive and new: Summit RacingĀ® Standard Timing Sets SUM-G6502
yeah, Ill get an old matched set with some stretch in it and my cam timing will be a little retarded but it wont be sloppy. Im not wringing out the last 2HP from this. Whats some real world cam retard degrees on a worn chain?