Long story short a car was run out of oil and I replaced the block and head with a new one. I assumed everything from the old engine would still work but apparently something is wrong. After the swap, it really acted sluggish taking off big time, and the same day O got it going and gave it back to the person it died on the side of the interstate on them. They said slowly it went slower and slower and the engine revved up (I think they were accelerating to compensate and then the tranny downshifted). So, here are all of the diagnostics that I've done. Prior to this the CEL was on for an O2 sensor, it still is as the manifold and sensors were reused. Ignition timing is definitely right, the plugs are good, the cap and wires are good, there is spark per my timing light (distributor seems perfect), I can unplug the fuel injectors and the car will start to start up and run (presumably from pushing the excess gas out, leaning out enough to run, then of course starving from there being no more fuel). I tried three different fuel pressure regulators and no luck. My best assessment is that it is running too rick. The only things that affect the air/fuel ratio are the MAP sensor, coolant temperature sensors, O2 sensors, and that's it right? Or am I missing something? Could a clogged cat create these symptoms? Cam sensor? Thanks in advance to anyone with any useful input.