Head, tb, intake porting worth it???

[gtp6515]

I am looking at going a little larger cam, and am looking at having some items ported, and maybe an ud pulley. I am at 380 whp (dynojet in 3rd gear), which from what I have seen is quite low for my setup. I talked to a couple vendors regarding head work, a little milling, hollow intake valves, and ss larger exhaust valves. I am getting approx 15 whp from one vendor, and 25-30 from another, just on the head porting. Anyone on here have any real world experience with this (dyno graphs)? If this is the case, between all these mods, I would be adding about 40-50 extra hp for about $1700, plus whatever gains from a slightly larger cam. Pat G spec'd me a 222/226 115 + 3 and 597/597(with a stock stall), so this should net me another 10-15? I also seem to read that the L92 heads dont need much head work, if any, due to them being so great to start with. Are heads worth it? It may be the larger the cam, the more increase there would be. I am sure there are a lot of great machine shops, but I have one I am very interested in. I am trying to make sure the $$$ I spend is worthwhile. Thanks so much for any input.