Reatta89

Bringing back to life a 67 289, Factory Air, A/T, Power Disc brakes, 102K miles that has been stored in my garage for 27 years. Since 1967 I did not pay attention to the assembly screws anytime I overhauled my Autolite, 4300-4V Carburator. According to the parts breakdown and a caution at the bottom of the overhaul instructions, one assembly screw at the driver firewall side of the carb is different from the other 10. Anyone know why or what difference it makes? Does anyone know if this screw or a new set is available anywhere?