I'm in the same club with Clyde as far as not actually having done the 216 to 235 swap. The thought I had was which clutch fork is being used?
If the pivot ratio is more than it should be then the movement of the pressure plate might not be enough to completely release the clutch disc. Pedal travel may be enough but when all the geometry of the linkage and fork ratios are added in you simply may not have enough travel at the throw out bearing. If it is any help I discovered when building the clutch linkage for the 250 in my 37 Chevy that the throw out bearing needed a little less than 3/4 inch travel to completely release the pressure plate. This is a standard 10.4 inch diaphragm clutch and is operated with a clutch fork that has a 2 to 1 ratio - the part of the fork outside the bellhousing needs to move about 1 & 1/2 inches to push the t.o. brg @ 3/4 inch. The pedal can move a mile but it's what is happening at the clutch fork that will matter.
Hope at least it gives you a place to begin checking before tearing things all apart.
Mike
