[ford38v8]

There are both advantages and disadvantages.

Pro - Your exhaust note with duals will be awesome!
Pro - Your carburetor will not boil over anymore.
Pro - Your engine will gain a vary slight raise in horsepower due to a colder intake.
Pro - You will gain bragging rights on your oldtime hotrod modification.

Con - Your exhaust note will be louder.
Con - Your carburetor will need to be choked until your engine is fully warmed up.
Con - High speed driving may tend to burn your center cylinder exhaust valves over a long period time.

If you do it, be sure to use wheatstalk pennies. The new pennies don't have the metalurgy that the old ones had, and may burn out whereas the copper pennies won't.