If you live where the winters are cold the simplest way is to get the
combined cast iron intake/exhaust manifold which improves early cold weather
driveability and also give you the double downpipe without the problems of
half washers, spotfacing manifold flanges, etc.
In response to those who say "You don't want to heat the intake!",
under max power the intake goes through so fast that it cools the manifold and
doesn't get heated much. And on those subzero mornings it makes the car
driveable in the first minute after you start it.
--
George Downs Bartlesville, Heart of the USA!