1996 Jimmy multiple misfires

[600cuin]

I have a 1996 Jimmy that runs rough, fuel pressure is 54 lbs.

We have replaced the spark plugs and wires, distributer cap (3 diff times) and the rotor button, fuel filter. When tested on the machine it read that it has mutiple misfires specifically on 5 & 6, but there was history of some misfires on all the other ones. (While on the computer with the truck running, the misfires occured specifically on 5&6)

Took the spider off and cleaned it with carbeurator cleaner and put it back on, now it starts harder and still idles rough.

Should we buy a new spider or change the fuel pump 1st.

We were told to get an actual GM distributer cap, but then they remembered that we had put 3 on prior, and told us then possibly buy the spider. Then some things I have read on the internet, some have changed the fuel pump to solve the problem...