My truck will not Rev past 3000 rpm all of the time

[kennythewelder]

This does not seem to be a transmission-sourced problem...

Perhaps @kennythewelder or @Old77 can move it to the Engine Performance and Maintenance sub-forum?

Done.

 

[Schurkey]

First thing first, test your fuel pressure for sure.
At prime, at idle, revved up.
Do you have a code reader or better yet, a scanner with live data?

I am less-generous than Drunkcanuk. "Code readers" are crap.

A scan tool (preferably) or a software + dongle or connector cable + computer or smartphone is so much better than a code reader that it doesn't make sense to even sell code-readers.

I do not but my buddy does. Last time I looked at my codes all i had was a O2 sensor code P0158. He also has a fuel pressure tester so we could do those at the time.

Codes are sometimes useful. The real diagnostic power is in the data stream.

Misfire counts per cylinder, fuel trims, spark advance/knock sensor readings will be important to know, as well as fuel pressure. Verify EVERY sensor and computer output.

What brand of distributor cap did you install? Vortecs are sensitive to distributor cap problems, and have numerous distributor issues such as worn bushings and failing distributor gears.

You can install fuel pumps all day long, but a new pump does not correct corroded wiring or defective wiring harness connectors/relays/switches. You NEED to verify pressure at prime, idle, and under load.

The OEM poppet spider injectors are a known weakness.

 

[GoToGuy]

With everything having been changed, assuming fuel pressure is good. There's a very good chance your OE poppet injection is at the end of life. Really old O2 sensors, change them out, they get lazy and slow. Poor engine operation isn't helping your cats.