Mike, here is a picture of the set up i have. and i guess that i was wrong, my system is not supposed to be pressurized, it is just designed to operate at less than 212 deg. F.

Very interesting. I've not seen anything like it. Someone with more GMC experience will have to chime in. I do see what looks like your overflow just above the radiator hose in your picture on the top of the tank. With that set-up it's definitely a non pressurized system.

@35mike here are some pics for you.....now that i can post them.

@hoseman-2 

Beautiful !!

I notice though that the above picture and the picture in your other thread show the vehicle with different wheels?  Is there a story behind that?  🙂

@ole-olson the profile picture with what i assume are original "War Wheels" was taken by the guy i bought it from. A few of them were badly rusted so he replaced them all and put some really nice rubber on it at the same time. I have 1 of the original tire/wheels that is in good shape. It was bolted underneath in the spare carrier set-up but i'm not bothering with that right now. I have also obtained some rally wheel center hub covers but i have the original GMC center caps.

@hoseman-2 

I like it.

A lot!

Really like the colors too.  (Looks like the same colors on my '46, Brewster Green, Kildare Green, and Black of course)

PS

Welcome to the site.

Nice to see a new owner of an old Chevrolet truck