[Tigers] More cubes for Tiger

[RObin Young]

Robin
	This was early smog control.  Ford used the thermactor emission
control system or T/E.  An air pump was used to pump air into each exhaust
port.  Later heads have an internal passage for the air.

Ron Fraser

Thank you Ron;  Is it then advisable to remove the lob from the heads when
the heads are machined.  I added the hardened seats, screw in studs and
completely ported the heads.  Was removing the lob the right thing to do for
efficiency and power?  RObin