I remember working on those Spacers when they were about new.
You did know the doors are different lengths by quite a bit?
Hinge pins and bushings....geez, we couldn't keep them on the shelves with the weight of those huge doors.
Initial high failure was the pigtail harness and pickup assembly inside the distributor. Started keeping those on the shelf, too.
Then we started in with manifolds, heads, head gaskets....you do know they were designed for a Wankel then an in-line 4?
Heavy as the Spacer ended up being, the stock Rambler six went into them.
Except:
The back two cylinders were under the cowl.
You could get the head and manifolds out, but it was a trick taking rockers loose, first four cylinder's worth of pushrods out (plus one, I think), pull the others up to the height of the rocker studs and tape them together, then pull the assembly out.
More than one guy who worked for us would put the head back on, manifolds, exhaust, then go to drop in pushrods and install rockers....only to discover he had to pull it all apart again.
Been too many decades now....but didn't they use the Ramble trunnion bits in the front suspension?
I HATED those "cars"....