the problem that i am having is that I just install a new engine head i started it up and notice that it was running rough did a check on each spark plug wire and found that it was not fireing on number 2 and 3 cylinder so I did a compresion test and found that the compersion was the same on each cylinder (150), so I change the spark plugs no diffrence change the dist cap and rotor still no diffrence ,change the spark plug wires started it still no diffrence do you think there is something wrong with the head ? 'help'