2 1/8" Header options

[BossHogg69]

So I've got a 532" BB in the works - (Dart block 4.6" bore x 4.0" stroke) and I'm looking for a set of headers to go along with it. And before anyone questions the need for a 2 1/8" header, the motor with be around 775-800hp (N/A) & 7,000+ rpm, so I really don't want to comprise with a 2" primary. I am running factory stock inner fenders and the truck is lowered 5" in front, so any low hanging stuff is out of the question. On the 468" that I blew up a few months back I was running a set of Hedman Elites that were listed for a Chevelle/Monte Carlo/Camaro (68-72) and they fit well, but were only 1 3/4" primaries. Does anyone have any experience with something like this in a stock type chassis? I called Lemon's Headers (supposedly 'custom') but they don't do anything in 2 1/8" for the 67-72's, only 73-up. Most of the listings on Summit & Jeg's for BB headers (1 3/4") show the application listing from '67-87, so maybe the Lemon's 2 1/8" for 73-87 will fit, but I dont' want to drop $1400 to find out, since I can't return them. Another option would be a couple 2 1/8" listings I found for 68-72 Chevelles and 67-69 Camaros, but again, I don't want to waste time and money only to figure out they won't fit. I do plan on getting whatever headers I decide on in raw steel, so if they aren't perfect, I can make some 'adjustments' before having them coated.

Any insight is appreciated, sorry for the lengthy post.

edit: I'm running the '72 clamshell style motor mounts and have already trimmed them to fit the Chevelle headers I was previously running.