I have a few questions on PMO manifolds that I am hoping the brain trust can help me answer. I Know this is a simple question, but as a Porsche neophyte, I know nothing and can use all the help I can get.

Question is, I am in need of manifolds and have been considering and would like to use the tall PMO's. They are advertised as being 37mm on the intake ports. Their standard short manifolds are 36mm. Why did they do this?

My 2.7 heads, built by Supertec, have been ported to 'S' specs with the 36mm intake and 35mm exhaust ports. It seems to me that the tall manifolds being at 37mm wouldn't properly fit my heads?

If anybody can point my in the right direction or fill me in on why PMO uses 37mm on their tall manifolds, and whether or not I can use these on my heads, I'd greatly appreciate the help!

Thanks in advance!