Yeah I'm afraid for 1-7/8" your going to be fabing your own, And unless you have heads with the Stahl bolt patern you will need the adapter flanges. 1-7/8 is a big tube!
Here's the set of 1-7/8 long tube headers the local fabricator made for my 66.I started the project and promptly discovered, there is good reason they get the money they get to mke custom headers! WOW what a pain!
Getting them up high in the chassis, clearing everything,, takes an artist not just a guy with a welder (aka: me)