I'm in the process of putting a 383 in my camaro right now and I'm looking at header choices. I currently have a set of hedman full length headers with 1 5/8 primaries that fit very well. My new motor should be about 450hp so I'm wanting 1 3/4 primaries to avoid choking the motor at high rpm's. Or would the 1 5/8 hedmans that I have now be big enough?
I found out that hedman makes a set of competition series 1 3/4 full length headers but I have never seen them or heard of anyone having them so I don't know how well they fit or what mods need to be made for them? I've heard mixed reviews of the hooker 1 3/4 LT headers, some say that they don't fit well. Anyone have any opinions on which header is the best choice?

Thanks