Failing emissions

[Jerry77]

This is my first post. I searched this forum for "emissions"; but only 5 posts showed up. Maybe someone can direct me to proper posts.
I have a 1989 5.0 speed density, 5 speed, all 100% bone stock in a 1984 Tbird. The engine has 180,000 miles, uses 1 qt every 700 miles, still pulls to 5000 rpm & has "very mild" detenation.
Last year,2003, I replaced the TAD,TAB,EGR solenoids, EGR position sensor, O2 sensors, plugs,rotor,cap, throttle position sensor,MAP sensor and the 2 catalytic converters. I checked the air pump and it's related check valves, etc; and I removed the EGR valve and scraped all the carbon off and replaced it.
My problem is I almost failed the 2004 Texas emissions test. Here are my printouts:
2004 25MPH dyno(1508 rpm)
HC: 157 MAX----I HAD 87 PPM
CO: 1.00MAX---HAD .02%
CO2: --------------HAD 13.6%
O2: ---------------HAD 2.1%
NOx: 1121--------HAD254PPM

15MPH (1342RPM)
HC: 162 MAX-------HAD159 PPM
CO: .91 MAX--------HAD.03%
CO2: ----------------HAD 13.7%
O2: ------------------HAD 2.0%
NOx: 1227MAX-----HAD353
---------------------------------------------------------------
2003 25MPH(1451RPM)
HC: 157MAX--------HAD 60PPM
CO: 1.00MAX-------HAD 0.0 %
CO2:-----------------HAD 12.4%
O2: ------------------HAD 3.6%
15MPH(1306)
HC: 162MAX--------HAD 100ppM
CO: .091MAX-------HAD0.0%
CO2: ----------------HAD 12.5%
O2: ------------------HAD 3.4%
----------------------------------------------------------------
OLDER EMISSIONS PARAMETERS
2002 HIGH SPEED(2394RPM)
HC: 220MAX-------HAD 5 PPM
LOW SPEED(872RPM)
HC: 220MAX------HAD 7PPM
--------------------------------------------------------------
Can anyone suggest hat might have caused the rapid rise in the HC levels. Note that I tested HC at 159 ppm out of 162 ppm in 2004.
I replaced all the parts in 2003 and passed with flying colors; but I did NOTHNG for 2004 and almost failed.
Does anyone know what I may need to check to get the HC levels down and why the rapid rise in HC levels in 1 year.
Excuse the long post.