My understanding is that the most restrictive part of the induction is one inch before the intake valve. And that the most restrictive part of the exhaust is one inch after the exhaust valve. Is this correct? If so, I imagine a simple gasket match porting job will not suffiice. Any recommendations for a first time porter. Trying to keep it simple here. Just clean it all up so it flows as if it were off of the assembly line; perhaps a little better. The engine in question is a 69 GS 400. Ciao
http://www.sa-motorsports.com/diyport.shtm Hopefully those links will help you start off in the right direction.
