High HC's is caused by an incomplete fuel burn or from running rich. What are the numbers? A new cat can knock the HC's down abut 100 or so and would be the cheapest place to start when you start replacing items. A failing/lazy O2 sensor will also cause it to run rich. You should also pull and check the EGR valve and PCV valves either if those get clogged it can also cause rich conditions. If you do have a 22re and not 22r an air leak in the intake after the AFM will also cause it to run rich.

More than tread lightly. Leave it like you were never there, nor anyone else.
'90 X-cab 4.88's 33 BFG AT's, rr ARB, Headers, Ignition upgrade, cold air induction.
'91 X-cab 5.29's 315's BFG MT's, rr ARB, custom bumper and flatbed