I am running the Schumacher tri Ys as well, great header, lots of space and with the ceramic coat lowered the temperature. However they are shorter, so the exhaust had to be lengthened a few inches. Call them up, the guy there is very knowledgeable.
1977 Chrysler Cordoba 440/TF-727/9 1/4 3.23 Suregrip
1985 Jeep CJ-7 256 L6/5-speed/AMC 20