Can anyone tell me what the 1" hole in the left upper area (near the firewall) of the passenger side foot well is for? Mine is open and I need to know if it should be plugged or should I leave it open. Thanks.

 

I have no idea. But if not being used I would put a rubber
plug in it until I found out if your driving it.

 

I am in the middle of reassembly and am applying dynomat on the floor and need to know if I should plug and cover it or cut the dynomat around it and leave it accessible. If I don't find out soon, I guess I can put a rubber plug in it and cut the dynomat around the plug just in case I need it. At this point I am just try to eliminate unnecessary work.

 

Likely was for a heater connection.

 

Good guess, but the truck had a heater in it (which needs restoration) and I know which holes are for those hose connections. I have 2 other cabs here and all have the hole punched out but I can't figure out what Ford used them for that all three cabs have them open. If these trucks had air conditioning I would think it is for the evaporator drain but that doesn't work here. So, aside from hoses and wiring, what the heck else would go through there. Keep in mind that the hole is not on the firewall proper but just below it on the angled part of the footwell on the passenger side.

 

I think what you are describing is the pathway for the speedometer cable to come into the cab

 

Yes, that's the hole alright! Well I guess I'll leave it open even though my speedometer cable attaches to the trans on the drivers side. I replaced the original 4 speed crash box with a 4 speed OD transmission out of a '86 F150. Thanks for the info!!