the angled valve job on the intake side helps out alot for fuel atomization to mix it with the air better..... id go with a 3 angle valve job on the intake side, maybe some oversized valves, itr springs and titanium retainers, port match the intake manifold to the head if you plan on going with the JG, and just use your stock GSR cams.... that head even with the stock cams can support some serious power.......