Has anyone gotten the MMR underdrive set. Is there any substantial difference between that and the Steeda?

 

Interesting thread here about possible things to consider...
http://forums.bradbarnett.net/index.php?showtopic=42537

the article is about a BMW setup, have no idea if it applies to the 4.6 ford at all...I dont even know if we have a harmonic balancer for sure(most engines do) nor if the underdrive pulley changes the balancer or just the pulley...havent even looked at mine yet- but food for thought...

 

Does anyone have any dyno results from either the MMR or Steeda pulleys?