P heads go for cheaper around 300 because it costs money for the headers, theirs not a big demand for them at a high price if you have to buy headers also. I got my gt40p heads on corral, valve job, new springs, scorpion 1.6rr's for 290, picked them up local...
Im in winter springs florida, ill sell you a set of gt40 non p heads for $350, you can pick them up.