68 340 Exhaust Manifolds vs TTi Shorty headers

That would be an interesting flip side to the testing of a basic stock 318 with manifolds, shorties, and then headers.
There's 2 dyno's of a stock 2bbl 318 (dyno trim) that I know of, but they only tested them with headers and made about 190 hp each, how much less with manifolds hard to say but I imagine would be around 10 or so hp less.