The stock fuel pump should be adequate, but it should be capable of meeting NEW pump specs. If unsure, replace. Use only premium grade pump gasoline (92+ octane) or unleaded racing fuel. In many instances, a high-output ignition system and a free-flowing exhaust system may benefit performance. WARNING: DO NOT use aftermarket chips or other devices that advance ignition timing, as detonation may occur. Actual performance gains will vary depending on the engine'™s condition and configuration. The system can be used on an engine with stock rods, pistons and crankshaft. However, at power levels of 140 and above, it is recommended that heavy-duty forged components be used.