Bleed the Coolant System, air vents? Options

[VavAlephVav]

so I recently did the water pump and while I had it apart I flushed through everything with the lower hose off and into the heater hose that connects to the front of the motor.
but I may not have gotten everything out as I had not yet removed the thermostat or water pump when I flushed it, yet I think I got most of it.
I've filled it up and checked it over the last couple weeks and it's not losing any coolant. yet when I start off down the road about once I've got it revved above 3k I hear a little
noise of the water circulating through the heater core. I still have awesome heat, this thing blasts me out and I have to crack the sunroof even when its 2 degrees outside.

So I wonder if I've just got some air still in the system since the heater core is probably the highest point in it. I read something somewhere that showed two air bleeder cocks in the system and one was right on the heater core connections in the firewall.
but I cant seem to identify them on the car, and I can't find the book I read that in and the other manuals I have don't show them.

Do any of you know where these are? or is it sufficient to just rev the motor up high with the cap off and hope that gets all the air out eventually?

[VavAlephVav]

I have noticed once or twice that it seems to have more smoke than I'd think it should. can't say that the performance is down much because I've only had it a short time.
'though I've thought maybe the exhaust sounds a little strange.
I do have a local shop that I used to replace a motor in this Astro van I had before I got the Celica, and they did a good job for a lot less than I would have thought ($600).

should they be able to tell whether it is just the head gasket, or an actual crack in the head before they actually open it up?
or do you just have to wait until it's taken apart to be sure, I know with an aluminum head once its been over heated it's a goner