I'll ask guys-

This car warm or cold, if you go full throttle- it just doesn't seem to pull smoothly. It seems like maybe at times it timing or fuel is running lean. I'd describe it as "notchy".
I put new injectors in it, no vacuum leaks. I read in the factory manual that early M103's could have loose crankshaft position sensor(at harmonic balancer) which can give erratic cold starts and should be replaced.

Looking for diagnosis help instead of throwing parts at it. It's not horrible by any means- just not perfectly correct. I bet it runs better than 95% of the 300E's out there.