No heat - any suggestions?

I'm assuming you have the hoses attached to the heater core, but if not, that would be the something missing.
Did you also replace your thermostat? That's a typical...
The heater core could also be plugged up, so you aren't getting any heat in it to use for the car interior.

Does your fan work so you get air, just not warm air?
It could be that air is not being directed through the heater - there are motor operated flaps that direct air flow in the venting system...

For got to mention that yes I put in a new factory thermostat. Have replaced the heater core. In 99 the vents are cable driven which all are moving freely and the doors are opening and closing.

Fan blows cold air over hot heater core and doesn't warm up.
Well, that can't happen unless physics stopped working in your vicinity...
Is there ANY temperature increase in your incoming air over ambient?
Does your fan work so you get air, just not very warm air?
Assuming you have a functional fan... your options are:
- Heater core does not heat up even though you replaced it.
There may be an air bubble in the core so coolant isn't circulating through it...
- If the heater core is heating up and the air doesn't, air coming through your vents isn't going through the heat exchanger.
Maybe a blockage in the vent line, or the door that really counts isn't opening.
Good luck.