Could I be floating my valves?

[HiFlow5 0]

Originally posted by PKRWUD
Are you sure it's not an exhaust leak?

Take care,
-Chris

You know I had thought that a few months ago, and tightened a few loose headers bolts, but still ticked. Now that you mention that, when I was installing my headers on the new motor, the headers wouldn't match up to the bolt holes. We had to oval the holes in the headers to get the bolts to fit. I thought that was pretty weird, cause they were suppose to be stock heads, and the headers fit fine on the old motor. Would doing that create a exhaust leak? Would it be possiable when i bought my long block the builder put on GT40P's instead of stock ones?