Great day for porting

Yeah that's the BIG difference in what I observe-the starting point. An OOTB Eddy RPM--Goes 257-263 cfm on my bench untouched--Heck a OOTB Victor does 278-285 as a starting point. I've got some SideWinders here ported by a BIG name guru here that I was asked to flow that peak at a whopping 287cfm--sold as flowing 318+cfm! The customer was pissed as he thought they were stock--I assured the customer that OOTB they would be in the 257-263 cfm range--He felt a little better but not much. J.Rob

@67autocross

might be coincidence, but the Promaxx BBM heads are known to be the same castings as the Sidewinders, the CNC ported heads are advertised as flowing 318cfm at .600"