Assuming the dyno numbers are correct and that the engine is working properly then I'd say your port size is too small. If the ports are the correct size for that engine then it should make a lot more power. The headers are big enough and so is the cam and a tunnel ram should support the power so that leaves the ports as the likely problem. But before jumped all the way to that conclusion I'd check everything over while the engine is on the dyno. Do all plugs look good? Are the EGTs fairly even? Did you check intake vacuum at WOT? Double check firing order? Run a compression check, a leak down, etc.? There are so many ways that engines can get messed up on the dyno you could write a book about it.
Were you really running 9 inches of vacuum at WOT? That is probably a bad number but if it is real then that would be an issue.
Andy,
All plugs looked great, and yes I looked at them. I don't remember the EGT's and I don't have anything in front of me to see. But the O2 readings are posted and shows a little lean. Engine was really responsive and firing order was verified. If you look at the blow by numbers you will see the measured blow by was 1.8 cfm at it's highest. Every pull the numbers got better indicating the rings were sealing.
The 9 inches of vacuum was what the vacuum pump was pulling, not manifold vacuum. We didn't have a sensor in the manifold, and if we did I would expect a serious drop at full throttle.
Dave
