[spidertri]

So, I bought my car with the AA headers already installed and when I was under it the other day I noticed that the header/midpipe connection looked like it might be leaking. Not from the flange faces but from the fact that the header flange holes were slotted to bolt up to the stock midpipe for some reason.

For the people who have installed them yourselves, is it necessary to drill the header flange like that to get it to bolt up to the midpipe?