I have a 93 ranger 4.0 with a V-1 vortec supercharger. It has 24 pounder (light blue) injectors. I have always had an octane ping and full boost if not running 112 octane gas. I am replacing the injectors duo to a dead miss. Should I go up or down on injector poundage to help with the ping.

 

How much boost are you running?

You could be loosing fuel pressure at high demand, it should be close to 40psi on a '93 and not drop below say 38psi to be safe with your setup, N/A 30psi is fine

If injectors are too large then idle will be crappy along with low RPM performance, too much fuel coming at minimum injector pulse.

There are many fuel injector calculators on line
If your target Horse Power is 300
6 injectors
Supercharger
BSFC 0.55
Fuel Pressure 40-45psi

Then you would be at 34lbs injectors

If fuel pressure is only 30psi then 41lbs

Big difference

You know what HP you might have, I don't.
You know or should get the Fuel Pressure, it is very important for this pressure to be constant thru out the RPM range.
40-45psi is the best range

 

I am running 8 pounds of boost. The fuel pressure is running 35psi at idle and 40psi under a load. Something I need to check today is the FMU. I need to figure out what disc is in it. If the 12:1 air to fuel ratio disc is in it I need to run 19 pound injectors. I wI'll look up the calculator today also.

 

Seems too low IMO

At 8psi boost, and no other modifications, you would expect the 4.0l's 160HP to be close to 225HP
That would put injectors at 28lbs at 35-40psi fuel pressure

 

Well I took the fuel system apart today and found that that the T Rex pump on the frame rail was not working at all. The injectors where full of gunk. The in tank pump was 10 shades of rust and the strainer was broken off the bottom and just laying in the tank. I have decision's to make now. How much fuel do I want to feed this truck. And how much HP do I want out of it

 

I guess that would account for the pinging at all RPMs

IMO, without upgrading engine parts, 8psi boost would be max.
And that should put you at 215-225 HP
And that's assuming 145HP at rear wheels, with 4.0l OHV it is probably closer to 135HP