The data for the graph below was taken off the printout from a rolling road shootout at Interpro. It was measured the day after fitting the head, at 500 miles. The results were not temperature corrected. The results support what I had experienced on the road. Accleration was better but top speed had not shown much of an increase. Torque looks to be around the 140 lb-ft mark, about an 8% improvement. Peak power was just into the 140s, allowing for temperature correction and the coking process, I don't think 145BHP would be a bad estimate of current power.

These results are very encouraging. I'm hoping that a more detailed set up with a Vernier cam pulley will allow some more power to be extracted.