Ok well I got the Hooker Super Comps for my GTA. They are the short tube design and I think 2055 is the number. I might be wrong. Anyway, I was wondering why the end of each header is narrowed down so much? The outlet of them that goes into the y-pipe is alot narrower than the rest of it. Should I grind some off to support better flow or is this some kind of tuning thing Hooker did with these headers? Maybe it is a dumb question but I dont want to hurt my performance any.

One more question while Im at it...what spark plugs do you guys use for the Iron Pro Topline 180cc heads? Ive been told 2 different ones but they either didnt fit or the part number wasnt right. Thanks.

When I received my headers and saw that small opening, I had the same questions. I emailed Hooker tech, and the response I got was that they have it that small to insure a good seal. Performance isn't affected because the exhaust gases have slowed down by the time they get there.

I also noticed their flange gasket openings were smaller than the primary openings and asked about that. They said the gasket material that sticks into the flow will burn away after awhile.

Now, Hooker has a great reputation, but I didn't much care for those answers (wonder if being bought out by Holley had any effect?). I did a fit check of the y-pipe and opened up the ball flange to 2-1/4" centered where the down pipes met (I found a high speed angle grinder was the only thing that would touch that stuff - die grinder wouldn't do squat). I haven't had any problems with leakage.

I also used FelPro gaskets that didn't block off the port openings.

I don't have an answer for your plug question. World recommends Accel 276 plugs, I used 276S for clearance.

so then you cut down some of that opening with a high speed angle grinder? I was thinking I could do some welding to help with the seal and I agree that it looks like it would promote a good seal. I appreciate your input but wonder what others have done. Has anyone else done this or have you just left it alone? Being that I will have a pretty healthy 355, I dont want to restrict my exhaust flow at all.

I need some more info on this from other people. What did everyone else do? I'm asking nicely.

I did the same thing five7kid did, thanks to him. Take his advice. It's good stuff. You made a good choice with the headers as well.

I installed them as is at first, then dropped the Y pipe and I could see where edge of the pipe was because the ball flange was black. I cut off only the area that was black on the ball flange so that it would still seal well without welding. It helped a little on the top end.