so if you port your heads put a cam in at the same time with the normal bolt ons.. and you will see about 300 RWHP.. its about 2000 for the head work and the cam.. and like 1000 for labor to take your head off.. minum you will see 45 to the wheels with port and cam.. you will need to get a chip cuzz it will move your peak HP to like 6200.. its cool for the street go do it..
if you do get the head work done, save yourself some time and money and get stainless steel oversized valves and valve springs to go with the new cams. Most aftermarket cams like to have the stronger springs anyways. Based on a few guys cars that I've seen, the VT engines cams are awesome. You can get a pair of those for around $550. You should see about 25 hp gains from the cams alone but if you get port work done and new headers (which would be a wise move seeing as to how you'll have the engine apart), you could get up to 45 to 50 hp from that. Slap a new upper intake plenum and TB on there to finish it off and you'll be set.