[LGAFF]

Primary in the head if 33......2ndry in the head is 36. Why not port the top of the head tp match? Bolt on the IH to the head, use a highligher marker attached to another hightlighter marker to reach down into the IH and mark the head port entry....it should be a cresent shape.

Tape off the area, buy a grinder or if you are really patient use a Dremel to match the port.

Regardless if you port match or not, you are going to flow better than the 31MM that the base of the IHs were as stock. You are gaining 2ndry flow as well. You can always come back later and have the heads done.

Let me know if you want to call me......Nothing to fear but fear itself. If you are going to epoxy the IHs, use the Morso product....not JB Weld.