I am amazed that Bill mentioned a proper signature has no plugs or wires. It'* awesome, but I haven't thought about it yet. Nice work.
On the L67 TB, do you have all the proper info on what to block off with JB weld? There are some things to change when you put an L67 TB on an L36 UIM. It would cost less than $10 in epoxy putty. Also with such a seal, you could port your L36 UIIM to 75mm or even larger if you really want to. No need to go aluminum if you aren't worried about cracks. Those cracks don't happen early anyway.