I got a full race manifold not long ago and I'm about to be putting the engine in soon and all I need is a wg. This is the manifold I have:
Full-Race Motorsports

My question is does that manifold use a 44mm wg? The reason why I ask is when I measure the in opening its exactly 40mm and the outside is 50mm. I'm a little bit confused on how do I know what wg do I need.