Everything worth putting on your car costs a bit when you're dealing with a Honda. The cost to power gain from all motor is definately not as good as it is with turbo. However, there are certain rewards in staying all motor as well. If you are not consuming any oil then I would definately leave the block alone and focus on spending some money on cams and valvetrain first then try to get a good header. If you keep a sharp eye out you can get a quality header used sometimes at a decent price. MR2JZKIDD can get a good deal on the Rage header which is a good unit at about the lowest price you will find for a quality header. I would focus on making those two things happen first. Mike can also get you a good deal on a cam package with cams, valvesprings, retainers. The type R valves are very good and I would just keep them in there as long as they are still in good shape. Most of the aftermarket basically just tried to copy the type R valves b/c they are that good.