ive got a 88 iroc with a TPI 355. i just bought some used headers from a guy and the ports are circle shaped.well ive got double hump heads on my car and i was wonderin if anyone knew if the exhaust ports were square or circle OR does it even matter.also, is it pretty hard to install the headers, do any accessories have to come off, ive got the serpentine system. preciate it

 

Are the headers longtubes? If so, you'd be much better off installing them from the bottom. Don't worry about the shape of the flange. Just get some gaskets that match the shape of the HEADER flange and you'll be good to go. And with any header install, have a few 6 packs around and set aside a couple of days to do it...makes it a lot less painless.

 

It doesn't make too much difference really. As long as the header tubes completely cover the port, you'll be fine. Wouldn't hurt to match up the port the the shape of the tube though. I think those heads would be round-ish (actually more square) ports though.

 

nah theyre not longtubes, they are shorties. also the dude i bought them from brought me the LT/LS1 style z28 exhaust tips today and he was supposed to bring the matching y-pipe but he said he cant find it. could i have my stock y-pipe modified to work with the headers and get the bung for the o2 sensor?
thanks for the feedback