'69 Barracuda T56 swap, floor, cross member
Stripped down AC/fan box, cleaned all the grime off of it, and bolted it to the firewall. The paint stir stick fits between heat vents and floor. Its a loose fit and past vent face toward firewall lots of room. So its only low clearance in middle and only around face of vents. 1 inch or so past vent face 1/4 - 1/2 inch clearance tons of room.
To get carpet in would prob have to loosen fire wall bolts, shove carpet under vents, then re tighten bolts. Maybe pull padding off back of carpet where clearance is tight too. But its looking like it will fit without any cutting welding of those floor vents.