'93 firebird with no heat

I have a '93 firebird formula that is having heat problems. I changed the thermostat to a 195 degree thermostat and still no heat. I then back flushed the system and nothing come out and still no heat. I also had a new radiator installed about 2 months ago. Any ideas on what could be causing this?
Is there something I should know about those bleed valves in the water line?
Before the radiator change I had good heat. But over the years I have had heating problems before.

Have you checked your heater core?

The heater core does not leak and I am able to push water through it with a garden hose.

I did a search bout this and heres what i found hopefully they'll be helpfull to you
http://www.automotiveforums.com/vbulletin/showthread.php?t=166322&highlight=heater
http://www.automotiveforums.com/vbulletin/showthread.php?t=344128&highlight=heater

Thanks much for that search Driftinggrifter2

New question. Is there any negative effect to removing the flow restrictor in the heater hose from the water pump to the heater core. This is the 3/4" line that gets restricted down to about 1/4". I had a leak in this hose and i intend on replacing the rubber part of this hose and not the metal portions. My intent was to replace this with a 3/4" hose with no restrictor. Is there any problem with this? Any help is appreciated.