Opinion on Clifford mods for Slant 6 motors

OK, my 2 cents worth, and worth every penny.
You mentioned about an opertunity to learn about doing it yourself. The slant is ideal for this. I have done several slants, both for racing, and for mileage. Building is different for these desires, but there are some mods that work for either/both. So, decide what you want to do. Raising compression is the main mod. How much, is determined by the end goal, as is the cam. As for clifford, the only things I would get, would be headers (for a race car) and/or intake manifold. Everything else is available elsewhere, at a better deal.

Edit: For 1967 and newer "A" bodies, Clifford is not the only source for headers.
For 66 and older, Clifford is the only source, as far as I know, and they do not fit with a 170 engine, or a 225 with power steering.