98 toyota camry

In replacing the heater core it was split do to to much pressure no water obviously, the radiato doesn’t seem to be circulating heater works when you rev it up what can be causing this high pressure i changed the tstat Could it be cloged radiator

One possibility for high pressure in the cooling system is a blown head gasket. I hope for your sake that this is not the cause of your problem.

Your conclusion as to the cause of your heater core failure is not necessarily true,how did you come to this conclusion?The radiator cap should relieve pressure long before heater core damage.

The phrase “no water obviously” makes me wonder what your getting at.

Well it sounds like you need a water pump for starters.  I also wonder about that "too much pressure thing.  Hi pressure should be relieved by the radiator cap.  From here it is hard to say if you have a clogged radiator,  but I would go along with VDC and suggest the head gasket idea could be true.