Hi Mike
All three of my 216 engines still have their original carbs all are Carter W-1 but they are not identical there were changes during the years of production. Carb at left is out of the 41 Pattern 12 one at right is the 1945 HUP carb.
Yes, I have noted that all of the engines seem to run richer, than when I first started driving them years ago. Do not know if this is the carbs or if it is that the gasoline has change a lot in the US.
The HUP with 216 has original oil bath, C60L with 235 has a 235 oil bath (throat is bigger) the C60S with the 261 has a modern paper filter could not find an oil bath that would fit the carb or the space.
The Carter W-1 on the HUP has been trouble free in 37 years of driving except for one time when I got a half a tank of water at a gas station. Ended up fixing the truck on the side of the road, drain the filter, remove the fuel bowel on the fuel pump, took the top of the carb and empty the water out . Fortunately I had only filled one tank at that station so was able to switch over to the other tank, then with the fuel line disconnected from the carb pumped the hand primer on the fuel pump until the lines were clear and gas going into the collection can was clear.
Because of the ethanol in the US gas I have discontinued using the mechanical fuel pumps on two of the trucks and replaced them with 6 volt electrics. On the HUP the original fuel pump is still in place and the fuel goes through it but it has a metal plate where the pump diaphragm would be used galvanized steel so it should not rust.
The two bigger trucks with the 261 and 235 engine have the correct carbs for the truck engine, got lucky and found the pair on e-bay NOS for under $50 US. Both were missing the same little check valve which is why they were still in the box as NOS because they didn't work correctly robbed the check valve from two non-functioning old carbs and they run great. Both are Rochester Carbs.
When I swapped engines on the 3 Tons I kept the original engines as complete units on engine stands, ready to reinstall should the need ever arise. Only thing missing fans and generators which moved over to the newer engines.
Cheers Phil