F-body Mac headers vs Fbody FLP headers
This picture shows the difference between the longtube FLP headers and the midlength MAC headers. The collector inner diameter is noted as well. |
How to port mac header primaries
Port them out using an air grinder or dremmel with a sanding bit. Key is to grind down the bump of weld all around inside each primary. |
Rocker Clearanceing for some double springs (Pic 1) View from bottom of rocker showing where to grind (using dremmel) |
Rocker Clearanceing for some double springs (Pic 2)
View from side of rocker showing where to grind (using dremmel) |
Stock LS1 PCV system layout NOTE: the layout of the LS6 PCV system is different |