Any chance you can put your old engine back on the dyno to verify? If you are running the same type engine as before it should read the same.
Break it down to the basics.
Fuel? what kind? Fresh? egt/o2 read correctly throughout the pulls?
Spark? strong or weak? locked or timing curve? sparking at right time?
Compression? compare cranking compression to factory specs. How much is the leakdown? should be well under 10% even for a used engine. A good warm engine should be ~4-8%