The 235 is probably the best choice, although you'll need to buy one of Dave's water pump relocating plates to use your 216 pump on it. There might also be an issue with the exhaust system- - - -most 216s used a straight down pipe, while later 235s had an angled exhaust. That also requires some monkey motion with the throttle linkage. If the 261 can be had at a reasonable price, grab it as a backup, and build it up at your leisure. The trashed 216 is probably a boat anchor, with the possible exception of the cylinder head and manifolds. Good luck!
Jerry
