Camshaft help.....340 Dart Swinger

The cam is cut with a specific Lobe Separation Angle (LSA). In the case of a XE268h, it's 110 degrees. You can't change that number once the cam is cut, it's fixed.

The intake centerline (ICL) is where the cam is installed in relation to the crankshaft. Cams cam be installed straight up at 110, advanced (xe268) at 106 or some number lower than 110 LSA or retarded at some number higher than 110.

Advancing gets the intake valve closed sooner and creates more cylinder pressure which can be helpful to trick an engine when using a cam that is likely a bit too large.