who can tell me the size of my combustion chambers in my stock 1989 c-1500 tbi 350? I am trying to figure which pistons to buy in order to produce a 9.0:1 compression ratio, without actually doing the syringe ordeal until it"s time to cc the chambers during the build. Does anyone have any experience with summit racing's map sensor vacuum pulsation modulator that is supposed to allow use of the stock ecm with more radical camshafts? Does the Edlebrock 4 injector TBI system preclude the use of the stock ecm? Is there anybody manufacturing anything that enables the use of 2 of the stock TBI units, along the lines of the crossfire system? Am I just pipe dreaming? I would prefer efi, and esc to carburetion, and mechanical ignition, if only for the preignition / detonation benifit. Sign me lost in the Quadrajet ages.