The Hyper-Pak setup does not fit with an unmodified '60-'61 direct-drive starter, or with a Chrysler or Nippondenso gear-reduction starter. I've been digging, and I think there is another likely starter option—so far unexplored—that looks like it might clear everything including the Hyper Pak rear exhaust manifold and maybe even the Dual Dutra Duals.

The candidate starter looks like this:



It is a coaxial (planetary) gear reduction design, not offset like the Chrysler and Nippondenso gear reduction starter designs. That's why the motor housing is directly in line with the starter drive axis, thus making the whole starter more "laterally compact". It looks like it should hug the block of a slant-6, with only the solenoid protruding. It is from a 2005-2008 Dodge Ram pickup with 5.7-litre V8 engine and manual transmission (automatic is totally different, stands no chance of fitting our cars).

Per all the book specs and dimensions it looks like it should fit and work on slant-6 applications originally equipped with a gear-reduction starter (all US '62-up except trucks with HD transmission and a few '70-'71 cars; all Canadian '62s and '67-up except a few HD, etc.) if only the upper mount hole has the threads drilled/reamed out. I've been meaning to fetch one, mount it, try it out, and take some measurements, but my to-do list is just impossibly long and I probably won't get around to it in the foreseeable future. So, please, someone else go try this—there are two questions here (does this starter fit and work on a '62-up slant-6, and does this starter clear the exotic manifolds). Knowing the answer to just one of these questions would be a good start (heh), so if you have easy access to such a starter, please try it out even if you haven't got a Hyper-Pak or DDDs.