B model firewall plug

[SuperB]

Would anyone happen to have any info and/or pics of the plug that covers the approx 5" hole in the lower passenger side of a B model firewall? I "think" it's for the hot air intake to the air cleaner (?), if the truck came with that option. Mine did not have the hot air set-up. If a cover is supposed to be there, I'd also be interested in rounding up the right parts. Any help would be greatly appreciated. Thanks  

[Draggin Wagon]

Think I used a peanut butter jar top. Not OEM but will do till you find correct piece

[Mean Green]

I think I put a big plastic shipping plug in mine and painted over it

[Mike]

My B-61 has a piece of cut-out metal inside the hole. I guess you can be a real Mack Engineer and come up with whatever you feel the need to get ur dun.

[chillywilly]

I have same issue, 1960 B-73, about ready to sandblast and paint. It appears the holes were unused due to longer hood , but the cab needed air.....i gave up trying to figure out the set -up. My B-61 uses both holes to accept air into the cab and pipe it on out to engine.

Somebody put coffee can lid type light metal. Kinda funny, reminded me of my patch work in the good old days.

I googled "4.5 inch freeze plug" and found many possibilities. No freeze plugs that large, but many other plugs for testing and plumbing. I ordered 2 pipe expansion plugs for $50 a piece and was very pleased....they will have a factory appearance as well as an unusual appearance after painting. They have a wingnut in the center, and will appear factory design.

BTW- my 2 holes are slightly different- one is 4.5in and the other is ~~4.4in   I can find the box if you want to consider them....I cannot find my order e-mails and receipt.......the place was in Florida