After more trial fitting, it has become apparent that the engine will not go in there without removing the shelf for the heater box and the ducting underneath it (The back of the engine block hits the ducting). I went ahead and took the battery tray out as well. This provides a lot of room to the rear. You could put a straight six in there with this part out. In fact one person did put a Jaguar DOHC six in one. It should also make taking the engine and transmission in and out a WHOLE lot easier.
original heater/battery tray:
heater box and battery tray - original by
Kevin Frank, on Flickr
heater/battery tray removed:
heater box and battery tray - removed by
Kevin Frank, on Flickr
Once I have the engine where it needs to be I'll look at rebuilding a spot for the heater. I can do without A/C if I have to, but a heater is important, even if it's only to defog the windshield. The battery will be relocated elsewhere.
Getting that shelf out wasn't easy. I had to drill out a bunch of spot welds, make cuts with the plasma cutter, and do the fine cutting with a cut-off wheel so that I didn't damage something I needed.