Denny, No 216 experience but I ran my 235 as a yr. round daily driver for 14 yr.@ approx. 12K mi/month, no problem. Doing the same with a 292 now. Been probably 20 days over 115 deg. this season already. Look at some old pics of building Boulder Dam in Vegas, for example, if you need some inspiration how good these old motors are.
As a side note, I've never used lead substitute in the gas, either.
Doug