Ok, So I need to replace the fuel pressure regulator on my 89 4.3 s10
4x4. I got my hands on good condition tbi unit with 1 bad injector.
Out of the two units I want to put together the best unit I can.  The
new tbi is a refurbished one, it has been cleaned, painted, new IAC,
TPS, a working fuel pressure regulator. One working injector pod, and
One non-working injector pod. On my old (current) TBI unit, I believe
everything is working properly except for the ruptured fuel pressure
regulator. A few questions

1. Am I better off using the old unit, and just replacing the top
half, fuel meter part, which includes the fuel pressure regulator?
  Or am I better off just taking one of the injector pods from the
old unit and installing it in the new unit and using that?

2. Can I mix the injector pods, or are they better off staying in
pairs?

3. While I have it apart is there a way to clean out the injector pods
really good? I think I read some where a way of placing the pod in a
bowl of cleaner and attaching it to a battery to make it pulse. Any
help?

I kind of feel that it is 6 of 1 and Half a Dozen of the other. Either
way I have to disassemble them equally and I have been playing around
with my new unit and its pretty easy to take apart and put back
together. Part of me feels that if it ain't broke don't fix it, and I
should use as many old parts as possible. And the other part feels
that if I have new parts and its all taken apart that I might as well
put the new parts on.

Thanks