just rebuilt runs bad
you are a patient man ,in every sense of the word. if it were me,i would have already loaded it up on a trailer and taken it to the shop where they built the motor, and made one of those guys come out and watch while i pull off the whole front end of that motor and the timing chain cover and made them show me exactly how they degreed the cam and installed the chain.im betting the timing dots they used were not the correct marks and/or the crank is not in time with the camshaft. better yet,have yourself a new and comparable cam ,new in the box,and make them slide that puppy in there with a new double roller chain with the traditional timing marks and one slot keyway ,bolt it back together and fire it up,and i bet 10 to 1 it runs the way it should. just a suggestion and please dont take anything i say the wrong way.i feel your frustration,that is why i put together my own internals. im frustrated along with you because your machine shop should have already been all over this since you havent gone inside the motor and already gave them your busines and you would think they would want a happy customer at every expense...just a thought