Misfire at 2500 rpm

i would check your wires

carbed? Points or electronic? Year Make Model maybe?

It is a 302 bored 30 over with f303 cam, Unilite, blaster 3, Air gap intake, Holly 650 dp, windsor jr heads and 10.13:1 CR.
I think I'm expleaning my self wrong. The engine sounds good, but when I check it with the timing light it will skip sparks around 2500 rpm and up. #1 is the worst. At cold start skips like creasy at any rpm. I can confirm it because #1 spark plug looks dark. The rest of them look right in the money.
Anybody has an idea of how much power this combo sould make?

Only running good on four cylinders, I'd say about 150hp...
Check plug gap, condition of cap, rotor and plug wires, try moving the plug wires while observing the 'skip' condition to see if it changes, that will tell you if the plug wires are leaking/arcing. Are you running a ballast resistor to the coil? Is your unilite's power lead hooked to the +12v or coil side of the ballast resistor? It's supposed to be hooked to the coil side IIRC, to keep from burning up the module. The fact that you are observing the problem with a timing light means it has to be a problem in the ignition system, so worse case if you can't find it then start swapping out components, starting with the plugs, then the wires, then the distributor.

the bigger the cam the less the vacuum....

Get NEW plug-wires buddy.....

11" of vacuum sounds right on a 302 with those heads. Might gain a little more with some tuning.

As for the spark problems, check all the components as suggested. Try another coil if you have one, just to rule it out.