89 burb engine problem has me stumped!!

[Thing1]

I just replaced the heads on my 89 burb, and after geting it running, I cant seem to get it to run properly. I found that the cat. convertor was plugged(The bright red glow tipped me to this).
Then I replaced the cap and rotor, plugs (With proper gap), rechecked the rocker arm adjustment, timing is on (Via timing light), and finally the o2 sensor on the exhaust manifold has been replaced.
After all of this, I still have the problem of somewhat rough idling and when vehicle is placed into gear, idle drops down (Almost to stall) and then back up, but when the gas pedal is pressed down (Even floored) little to no acceleration comes along with it.
Any suggestions would be GREATLY appreciated!!
Want to have my ride back on the road so I dont have to keep using my wifes 99 Burb (She hates when I get it mud.. I mean 'dirty').

[Tuffdrvr88]

Check your TPS (Throttle Position Sensor), Idle Control Valve, and connect a Vaccum gauge to the throttle body the blip the throttle. The needle should drop then you should get AROUND 17 inches of vaccum just to make sure everything is sealed alright. You could also pop the hood on a dark night and look for arcing. Sometimes if the wires go bad or get too close to a nice piece of metal the spark would like to jump to you will get that miss or rough idle. Have you checked compression?

[2000CAYukon]

Originally Posted by Thing1

I just replaced the heads on my 89 burb, and after geting it running, I cant seem to get it to run properly. I found that the cat. convertor was plugged(The bright red glow tipped me to this).
Then I replaced the cap and rotor, plugs (With proper gap), rechecked the rocker arm adjustment, timing is on (Via timing light), and finally the o2 sensor on the exhaust manifold has been replaced.
After all of this, I still have the problem of somewhat rough idling and when vehicle is placed into gear, idle drops down (Almost to stall) and then back up, but when the gas pedal is pressed down (Even floored) little to no acceleration comes along with it.
Any suggestions would be GREATLY appreciated!!
Want to have my ride back on the road so I dont have to keep using my wifes 99 Burb (She hates when I get it mud.. I mean 'dirty').

I have seen this more than once be the fact that the valves are adjusted too tight so it would help if you explain how tight you did them. For example, I move the push rod up and down while I start tighting the rocker arm. Once the push rod no longer goes up and down (zero lash) then I go a half turn. Some will go a full turn but this is what I do. Note that when the push rod no longer goes up and down it is still easy to rotate.

Other things to check:
1) Did you disconnect the ESC wire when you set the timing? 0 degrees with EST disconnected.
2) A stuck TCC can also cause your symptoms.
3) If you still have the stock air cleaner, the heat riser can stop working and only hot air goes into the air cleaner.
4) MAP does not hold vacuum, bad vacuum line to MAP, or bad MAP.

//2000CAYukon