I found information on this website from Geoff's 1968 Pontiac sales manual. Make me think. 55-4 is the custom trim option which includes many things not just deluxe interior. I dont know if it applies to 1967. I had been told it meant deluxe wheel discs. Perhaps it means more.

Here is what I found....


Firebird Custom Option

This impressive custom trim package, available on all Firebirds as an extra-cost option, is comprised of a select group of interior and exterior styling appointments especially designed to provide an added touch of elegance and luxury to these personal sports-type cars.






Interior Appointments:
° Custom-styled, slimline Strato-bucket front seats in all-expanded Morrokide. Strato-bench front seat also available at added cost.
° Seat and cushion inserts finished in attractive knit vinyl.
° Custom-formed vinyl door and quarter trim panels.
° Vinyl-coated taffeta perforated headlining in hardtop coupes.
° Bright, roof side-rail garnish moldings in hardtop coupes.
° Convenient flexible assist grip on instrument panel.
° Flexible pull handles with bright, decorative trim shields on doors.
° Attractive "Firebird" emblems on door panels and glove compartment.
° Deluxe steering wheel of energy absorbing, 3-spoke design.

Exterior Appointments:
° Bright metal wheel opening moldings at front and rear.
° Handsome, chrome-plated deluxe wheel discs.
° Dual horns.







A-8


Note: Not all custom trim Firebirds came with the above trim options (Code 554). Some came with standard interiors (224xx) while others came with custom interiors (226xx). All items in the Custom Trim Option could have been ordered individually on a 22467 (or 22437) car except the Deluxe Interior, 22667 (or 22637).