We bolted the block and tranny together and mocked them into the chassis to see what we have. As the photos show, we lucked out w/ the 2004R. All we had to do is move the frame brackets back a few inches (from the yellow pencil location) and narrow the stock '59 mount and it fits perfectly. The yoke has about half an inch play which is plenty since this half of the two- part drive shaft in these screwy GM X-frames doesn't move. We put the body on and we still have plenty of room to flatten the floor board so our Caddy power split bench/bucket seats can blot in.
We have most of the exhaust mocked in so now it's rebuild the tranny and engine, drop them permanently in the frame, bolt the body on, fit up the body panels and doors, do the final body work, etc., etc., etc. You know the drill.
If your Elky is like ours it is either missing those round hole covers in the tail fins/tail gate opening or on the ones you have the tabs are all rusted off to the point they won't stay in the holes. Not to worry! I found these nifty stainless steel sink hole covers @ Home Depot in the plumbing dept. Even says it's for an Elk(a)y! Any plumbing supply will carry a usable version, just be sure to get the 1.5" size. They are almost exact duplicates of the original Elky part except they are stainless which will last for ever and are prettier anyway. Get a couple only about $2.50 each.
Since we are opening the smugglers compartment to the interior for more access, we had to seal the roof of the compartment so water can't run into the interior. Here are a couple photos of the roof we are making from 16ga. It will have two drain tubes like the tubes the '59 uses to drain water from the window channels. We bead rolled a channel where the drains will go to collect the water. Everything will be epoxy primed and tar undercoated for perfect seal. Wood bed will go over the whole Elky bed floor.