I have a 2005 Chevy trailblazer ext Lt with over heating issues I replaced radiator, water pump, tstat, and clutch fan and still doing it I also checked for head gasket blow out its fine

Could be a clog somewhere in the cooling system in the engine block. Flush cooling system with Prestone Super radiator and Cooling System Flush.

Could it be something else

Do not know what else it could be seems you have covered all the other reasons it would be over heating. Are you bleeding the air out of the system correctly ? That would be the only thing I can think of.

Is their any type of bleeder valve on this type of system I have th inline 6 4.2

Questions what was the reason you replace all the things you did was it over heating ?

Sorry about that asked the wrong question ment to say if it was over heating before doing all those thing do not think that air in the system is your problem more like a clogged cooling system.

But to bleed system remove over flow cap and leave off fill to full mark with anti freeze start vehicle and let idle when vehicle reaches operating temperature thermostat will start to open and anti freeze level will drop in the over flow tank when this happens add more anti freeze to over flow tank to full mark and put cap back on.