Note how much more air the ported LS3 heads can move than the LPE GMPP 243's. The LPE GMPP 243's were one of the very few cathedral ported heads to actually break 300cfm on this flow bench. A set of a high quality ported LS3 heads is very competitive with aftermarket cathedral heads but $1,000 less expensive. Summit has TFS 235's a pair costs $2,750 Add in cost of BBK $900 + porting $500 to $1000 $4,150 to $4,600