Update on my problem: The manifold has a circular hole about 5 cm. Still driving it until FLYBOY'S Exhaust SYS gets here. At first I thought that it was not involving the flow----but it is.

My HP is laggig a bit and the noise is quite annoying!

Some one said that I could cause damage to the valves when I drive it like this (due to influx of cold air).

Is this true or possible????????