hard block

"the engine never really got over 210 degres at the sending unit but i am sure below the heads it was"
Remember you're looking at indicated temperature of the coolant. If it isn't picking up any heat, that is not a valid indicator of engine temps. I'd bet the lower end got much hotter than you think becuase that heat never got into the coolant.

I don't know of any effective way to remove it. It's a permanent solution. As UOP said - by removing volume and surface area from the coolant system, you shift more cooling duties to the oiling system. If you "must" run a filled block , even 1/2 way, you really have to invest in an oil cooler, a higher volume sump, and I think it's a good idea to run an oil temp gage.