From the data I have those 2 carbs are not very different in size.
The 216 carb should have
Throttle = 1-1/2" diam
Venturi = 1-7/32" diam
About 122cfm at 1.5" hg
The 235 carb should have
Throttle = 1-9/16" diam
Venturi = 1-9/32" diam
About 136cfm at 1.5" Hg
I don't know what main jets are in each carb but that would be another way to compare if you know that.
I've run everthing from the smallest "B" carb at about 90cfm to the biggest "B" truck carb at 185cfm on my 250 six, of course the big carb runs better up high but they all run just fine as spares, I suspect it wont care about that little difference in size. Should make a good spare.
