505 dyno test results

I would have thought a pull to 6000 just to see wouldn't have been out of the question.

I agree. I at least would have attempted it.
If it didn’t want to go any higher than 5600, it’s as likely a lifter unhappiness issue as anything else.

Understand that power numbers vary from dyno to dyno, but that being said……..over 600hp from that combo wouldn’t be a bad number on the dyno here.

If the engine will need to rev past 5600 in the race car, which seems likely, you may have some sorting out left to do.