Yup, slave and fork here. There is more information available about the mods required for a a fork application than there are for the hydro unit.
Basically, depending on what brand replica you have, you have to modify (trim with grinder, saw etc) the bottom outside edge of the fork to clear the cars frame rail. The motor sits LOW. Then you need a plate (no big deal, can buy them) to mount your slave on. The "rod" between the slave and the fork can be as simple as a piece of "all thread" with a couple of "nuts" on it. In SOME cases the bell housing and bell housing "plate" need to be trimmed (saw, grinder, etc). There are pics and templates available for this. NOTE: On my ERA the bell housing DID NOT have to be trimmed. The "Fork" was, but I'm not sure it "had" to be.
On "Gasholes.com" under "Your Car" there are "threads" that have some great pics and commentary on how to do it. Also a "search" here on CC should turn up some good stuff.
Try "Gasholes.com", "Your Car", "Lakewood Bell housing pains" for one example.
http://www.gasholes.com/smf/index.php?topic=3819.0