The standard length ARC rod is number 6280, I believe that is the one E.C. lists as the model 28 rod. The billet counter weight link (dog-bone) is a much needed item, as the factory ones are prone to breaking and sending the balancer out the back of the block. If you have a crank with the removeable eccentrics, you could one up it and remove the balancer all together and install the ARC counter balance weights on the crank. The billet rod is also a good thing to have. These items wont really net you any more power (well, some due to less weight), but they help the engine live. You need to make a strong foundation before putting all the power into it. Once all the weak links have been addressed, then worry about cam, carb and so on. Putting in that expensive can, only to have a weak rod fail and break the cam on it's way out the block is no fun.