WERD

 

If you're running the RevUp engine, the MD MREV2 and 5/16 spacer is the only choice to go with. AAM spacer on the RevUp doesn't yeild much (if any) power gains and is on par in cost with the 5/16 spacer. The MREV2 is the hot ticket though. Definitely more expensive, but worth it if you're looking at plenum mods for '05+ RevUp engines.

 

MD

I've got the MREV2 lower collector & 5/16 spacer. Good combo.

 

MD-my 1/2" spacer arrives tomorrow to replace my cracked Crawford