I installed the water pump adapter on 4 engines,two-235's and two 261's,one of the 261' having typical hot rodding stuff.They all ran cooler at idle and down the road when compared to the usual short water pump.
The stock 216 water pump is driven around 1.4 times faster than the crank,the later low mounted pump spins a little less than crank speed.

70 Triumph 650 cc ECTA current record holder