Offy Aluminum 2x2 bbl intake for slant 6
Your post office "should" have large flat rate boxes that measure 24x12x3. They will hold a slant intake. They will also hold an early A (65/66) single plane 4 barrel - make sure to tape the hell out of it so edges don't poke through - that cast iron 4 barrel is heavy! Have used them to ship both!