I have just been catching up on this thread. So my 1951 1 Ton Canadian truck has the 216 version with the short side cover. I too had a crack at one of the exhaust seats. I had it repaired and it wasn't successful. I eventually found a head from a Canadian car with the casting number of 3835499. My old head had the Canadian casting number of 3695451.
By the way that is a beautiful truck you have there!