AHOY gents, got my old big valve head from a previous build, needs new valves and cleaning up.. question: which will be better running on a stock bottom end; 1. ported and flowed "stock" vr head 2. ported, flowed, 3 angled valves, big valved head im asking because last time i fitted this head my car didn't perform as well, prob due to the valves leaking, but will my stock ecu be able to handle it or is a chip a must? thanks