Dropping B16 With header into 90 Hatch

So… ya it’s the 1st gen b16A with an airmass header. dunno if it was made for the actual b16 or what, but anyways. it’s got a pretty big bang on the lower runners but it must do for now. after getting custom exhaust redone nad later on when i buy a new header, are all b16A headers the same in size/length? meaning, will I ahve to extend or shorten the ehxcaust pie to accomodate the new header or will the new header be a exact swap with my old so I can sue same flanges etc? basically. are all B16A headers same length in the end where it meets the exhaust pipping?