no need to go anywhere near the gt28's if your planning on staying at 200 bhp as you only need to be consuning about 25lb of air but i would put some of jano's rods in it then if you do want to up the power a bit then you can as standard crank and pistons will do 300 bhp so with steel rods no big worries, the head i am un sure of but in a couple of weeks when i get back from holiday were going to be flow testing a norris /jamsport/standard head to see just what you gets for your money and if they can be improved upon, cam stay with a standard one and go megasquirt as really simple and good results can be had with plenty of people starting to say they'll map it sure if any of the above is wrong we'll be told but i hope that helps you