I will soon begin the task of rebuilding the engine in my 97 Bonneville. The engine has a rod knock (car stuck in snow, high rpms, someone who doesn't know what the redline means). I plan on going thru the lower end and anything else that needs to repaired, replaced, measured or cleaned. Is it worth making performence improvements to the engine while I have it out and apart or does the "bolt on" performence equipment make more sense these days. Just looking for options