Mercruiser 5.7 overheating

Question
Good afternoon,
Bit of a long story but...
I have a 1995 210 Crownline cuddy with a 5.7 Engine # OF370406 Drive# OF376824
When I uncovered the boat this year I had new gear oil seeping from the water intakes on the lower drive. I purchased a new impeller kit that included the seals to fix the oil leak and I replaced the impeller and housing at the advice of many since I had the drive apart.Now I am having an ongoing overheating problem.At idle and no wake speed the engine runs at a steady 165, as soon as I throttle up and get on plane the temp will creep up to 225 and will continue to rise if I keep going until the high temp alarm goes off.The minute I slow down and move at no wake speed the temp drops right down to 165 and will stay there.I have had the drive apart three times since trying to make sure the water tube is mating properly and the new impeller is okay. This last time I installed the lower drive with the drive in the up position and I was able to guide the water tube onto the pick up with my hand as I pushed the drive into place.
I have replaced the thermostat and removed all six hoses from the housing and ran water thru them. I removed the risers, which seemed to be in pretty good shape and gave them a good cleaning and put them back with new gaskets. I also replaced the main water pump and I have tried running without the thermostat.I have ordered a new hose to replace the one coming from the outdrive to the power steering cooler. It felt a little "mushy" and I have been told a soft hose can collaspe at high rpm.
Any ideas or advice would be greatly appreciated....Thank you....mike in PA

Answer
when you changed the impeller did you replace the gasket under the wear plate on the water pump? if you did not have a overheat problem befor changing out the water pump impeller then more than likely you may have a leak at the pump itself. it sounds like you have checked everything else.

        bruce