You sure the Pro-1's are not 345's, or 325's? There isn't a Pro-1 380. There is 310, 325 and 345's. There is race series 360's and 320's. There is also 335 and 355 Pro-1's that are cnc ported. Otherwise, the only other 380cc conventional head, that isn't really conventional, from dart that is, is the 380 oval ports, that are 18 degree, but like a conventional head.
The Pro2 380's are pretty killer and will run with any of the other killer conventional heads. They also respond to additional work, and can really make power.
Frank