I bought the MP "Thin A-engine damper", part number 4452816, and it looks like a high quality part. Reason I bought that is because I want to run the stock pulleys and most after market dampers are thicker which would cause pulley alignment issues. Plus, even with the ported Eddie heads and 550 lift roller cam my 414 won't make much more power past 6,000 RPM. Unless you go with ported Indy heads and a real big cam the 4" motors aren't high RPM screamers.
