That would depend on what horsepower you want to get. That's one of the things that made horsepower readings drop in the mid seventies (not all of it from compression loss) and again later. Factory readings used to be without any accesories, using a dyno waterpump and equal length headers and outside air, that's the reason so many varied from what you actually got. Later they started running them with the factory pump and alternator, but I believe still with dyno headers and optimum air. Now days the readings are taken from an engine just as it is plugged into a car, accesories, exhaust manifolds and air intake, so even though current figures seem lower than those of long lamented times, they are more accurate and more closely reflect what you really get. So if you want an accurate reading run it as you would be putting it in the car, if you want bragging rights run it naked.
[ October 27, 2002: Message edited by: woodz428 ]</p>