You are headed towards a nice setup. It's like mine, although I have an LS7 block. If you go with the LS7 intake, you will need its fuel rail as the injectors are smaller than the LS6. You will therefore also need injector adaptors to fit your Gen 3 harness. The MAP sensor is in the front on the LS7 intake, although you could keep the stock location with some minor mods (hook the old MAP sensor to the intake using one of the nipples on the back of the intake with some vacuum hose). Otherwise, you'll need a MAP sensor harness extension. I assume you are using the GEN 3 cam and crank sensors, so no change here. I got my electronic harness extensions and adaptors from Katech, but I'm sure others have them. As for the rockers, I haven't seen any offerings from the aftermarket yet for the LS7 heads. Remember, the intake rockers are offset so your old rockers won't work. Good luck.