Chris is correct in saying the GE head flows better.
This was taken from Clubna-t.com
Stock GE head
lift---------intake-------exhaust
.100------91.8----------69.85
.200------161.33------130.38
.300------197.4--------154.23
.350------205.6--------156.35
.400------208.8--------157.62

Stock GTE head
lift-----------intake-------exhaust
.100"-------- 81---------65
.200" --------155-------122
.300"-------- 199-------145
.400"-------- 207------151

To answer your other questions. Yes they can handle the same amount of power. The only other slight differances are in the water pump since the NA feeds the head from the driver side and the TT from the passenger side. The NA block is not drilled for the oil feeds for the turbo since there isn't one. Also the oil pan is not tapped for the oil drain.