I recently swapped out a tired 216 with a freshly rebuilt 244 (235 bored 0.060" over) and the performance was noticeably improved.
I looked for a good rebuildable 261 but what I found was either non rebuildable or way out of my price range so I went with a 54 235. Everything improved and even though the 235 is highly modified it's avg'ing around 15.5 mpg while running with modern traffic.
Like John suggests, get it and rebuild it at your leisure while your 216 keeps purring on. Many parts will swap from the 216 and some you have to swap.
Depending upon your skill set, a total engine rebuild will run anywhere from $1500 - $3000. I farmed out the machine work and did my own reassembly then after breaking it in I let the engine sit a couple years before I did the swap.
As they say there's no replacement for displacement but keep in mind these Stovebolt engines are low rpm torquers, not high rpm screamers...
As Jerry says they're just glorified tractor engines LOL.
Good luck
Dave
