While loading my 1968 sport fury onto the trailer for Carlisle to try and sell it, the right side exhaust, caught part of the trailer and broke the right side HP exhaust manifold in 2 places and completely broke off the part that the head pipe bolts to. I have another HP exhaust manifold to...
They both appear to be '67 - '69 C Body HP manifolds and should work just fine with a 440. The right side manifold was used for several more years and was also used on B Body MOPARS for several years. It would help to know what car you would be putting these in.
The right side C Body (also B Body) HP exhaust manifold is the same from 68 - 72. The left side C Body HP exhaust manifold changed for 1970 and there was a different left side HP exhaust manifold for a 440 vs. a 383 for 70 - 72.
I'm pretty sure that TTI offers headers and a complete dual exhaust system for your car. As for exhaust manifolds, you are probably limited to C Body 318 manifolds for a 67 - 68 318, assuming that you don't have a poly head 318 in your car.