1968 Barracuda Notch - Plano, TX

Went ahead and cut a hole in the extra dash frame and extra dash pad to mock up a slightly different idea that insets the AC vent deeper and allows more leg clearance.

Actually think I have the way I will attach the vent sorted out also. The OEM has a round opening with 3 tabs. The opening is 3-1/2" ID, there is a flange inset 0.1" in with a 0.1" lip all the way around. 3 tabs that stick in 0.25" locate the vent and give the vent something to lock into. I can make a ring out of steel that is 0.2" thick with a machined lip that duplicates the OEM plastic bezel. Then weld that ring onto a metal pipe with a 3.5" ID. Weld that assembly into the dash frame. The vents will pop right in. Then I just clearance the dash pad and have it recovered by my local upholstery shop.

Pictures of the hole in the dash frame and the mock up I did today.