Are you sure the secondaries are opening?
What cam is in there and at what compression ratio?
From where I'm sitting, the only thing I see wrong is the tach.
I don't suppose your tach has one of those switchs on the back for matching it to the number of cylinders you have,eh? If it was set to 6cylinders instead of 8, the rpm offset at 2460 rpm could be very close to reading 3000.