Did you verify this valve is closed completely?:

Yeah valve is as tight as it goes

Well . . . you could plug it off, but you'd need to verify that this hose is rated for pressure. As a temporary step, you could plug it off and fill the system with the radiator cap loose and make sure there isn't something else that will leak with this hose not connected to it.

Otherwise I'm at a loss on this one. There isn't anything in that area for it to hook to.

Any chance of getting pictures from that area of the engine bay?

I put a bolt in it to plug it off then it over presureised my whole cooling system and started overheating and blowing coolant out the over flow on the resivor tank with the cap loose it still leaks like I got to much air in my system I've burped it a bunch gonna do a combustion gas test on it see if my head gasket is bad and pushing exsaughst into the system never had any head gasket give thease symptoms motor runs like a top with no outher signs its a head gasket oil looks good no coolant loss anywhere else no white smoke exc

That'* weird, LS 4.8/5.3 engines are pretty easy to purge. I've never seen one blow coolant out of the overflow tank without there being a much bigger problem, but LSes have so few heating issues that this has been rare. On the bright side, it probably wasn't over-pressurized with the cap loose, so no damage was done. Curious what you find.