dameeks Darren Those are good numbers for what you have in the motor. At 4 grand the valve spring may be going soft and not closing the valve as well. A b303 cam is small. This is a good motor for a cobra. You could put a backpressure gauge on your exhaust system and check for too much back pressure. 2 lbs is about perfect for the best of both worlds under WOT. Reliability is more important the the extra 5 hp you are looking for. What are you doing with the car??
Roadracing, Autocross, 1/4 mile, cruiser?? This is what you should build your motor for. Don't worry about HP, Build a tork motor good to 6000, You will be more than happy with what you have. I have a 452 that makes 358hp and 468 tork. 12.5 in the 1/4 mile and is very stretable. Something to think about. Tork makes it move, hp keeps it moving at high speed. Rick Lake