The firewall is part of the structure—not a cover panel.
Engine placement, bellhousing size, headers, steering, pedals and accessories all compete for space at the firewall. A recess may solve one interference and create another if those parts are not located first.
The most useful starting point is the assembled vehicle with its actual engine, transmission, steering and exhaust components in position. That allows the panel shape, seams and access areas to follow real hard points instead of estimates.
Transmission tunnel and driveline clearance
A transmission tunnel has to clear the transmission and driveline while preserving foot room, seat position and future service access. On a chassis-swapped or lowered vehicle, the floor may also need to rise or transition into the tunnel differently than stock.
- Confirm drivetrain position and movement before final shaping.
- Allow access to service points that would otherwise be buried.
- Carry beads, edges and transitions through adjoining floor sections.
- Check exhaust and heat-management needs before closing the structure.
One solved interference is not a finished system.
The firewall, floor and tunnel should be checked together so clearance in one area does not cost space or serviceability somewhere else.
Wheel tubs, suspension travel and truck bed raises
Wheel tubs are defined by more than tire width. Tire diameter, offset, suspension travel, axle movement and intended ride height determine the space the tire actually needs. In a lowered truck, the tub often becomes part of a larger raised-bed or floor structure.
Marco Sheetmetal plans the tub, supports, floor and chassis closeouts together. That creates usable clearance and a finished appearance without a universal box placed over the suspension.
What to send for a useful project review
Send the vehicle year and model, drivetrain, chassis and suspension details, tire size and offset, intended ride height, interior or bed goals, and clear photos of the current assembly. Marco Sheetmetal reviews custom firewall, transmission-tunnel, wheel-tub and truck-bed projects in Mesa for customers across Phoenix and Arizona.
See firewall and transmission-tunnel services →
See truck bed raise and wheel-tub services →