Did you port the M90? Your post was a bit unclear. If you haven't yet, you may want to get in touch with Mike Sitar at www.toohighpsi.com He had 2 of those on a 351 Windsow in a Turbo Coupe that went low 10's. He's an engineer with Eaton and could probably get you pointed in the right direction. He used to have pics of the port work on the web site, look around.