[Power Surge]

Okay, now I am more confused.... Low riser has bigger ports than Medium Riser? MR are listed as 1.40 x 2.10 and Low Riser are listed as 1.46 x 2.40.

My Blue Thunder MR intake has the smaller ports, but my 390 heads have the larger ports (mismatch is okay since it's smaller feeding to larger).

The gasket I had on there was FelPro 90145. They are the blue steel core Permatorques. I assume this is the same as the VR NitroSeals?

I will try the Nitroseals, but I obvously need the LR version for my big port heads.