Header flange to round pipe interface
If this were for a Jr. Dragster, I might try that, but there are SIX of these little puppies, and I'm afraid at my age (71), I'd "die of natural causes" before I got the last one done...
I thought that as long as slant 6's have been around (FIFTY YEARS???), and as much hot rodding as they have been involved with, that surely-to-goodness, SOMEBODY must have created some "labor savers" for poor souls like me who feel it necessary to fabricate a set of headers for this engine, for whatever reason.
In building slant-six headers, the manufacturers have to stamp out that square-to-round end for all 6 pipes that fit every single set of headers they manufacture. I was in hopes that one or two of these companies might use their imagination and create 4-inch-long pieces that would contain this square-to-round end that that they could sell to folks who want to build their own. Nobody, it seems, makes a bolt-on header for people building turbocharged slant sixes, so they MUST build their own, or hire it done at elevated prices.
I guess my hopes were not well-founded...