Back in the early 90's when i was building X-flow engines, i tried a whole host of different cams.

One came highly recommended by a company called 'Emerald'....(heard of them )

To cut a long story short, i plumped for the cam which was going to suit ther engine spec best and it never ran properly.

it was horrible to drive, produced no significant power than the engine was running and lost out everywhere else it should have gained.

After a short while i binned it and went to a Kent 244, no other changes and the difference you just wouldn't believe. the Kent cam pulled from idle and pulled to just over 7200rpm, and produced 156bhp at 6500rpm.

the Emerald cam should have made 155bhp according to Emerald, but made about 130........

Thats said, my very first engine was a 1300 x-flow and that made 115Bhp with a Kent BCF2 cam.

So like i say i am fully aware that experience goes along way, its cuts down the time between having an idea of which direction to go in with a tuning aspect and knowing how to get close to start with.....all comes from experience.