I've measured the Nissan and the Ford for comparison.
The Nissan is;
40mm lower, although the high point is at the front not the middle so probably a line ball for comparison,
80mm shorter, so this may compensate for the taller front as well by sliding it back down the angle of installation,
250mm narrower, which is significant as the offset cabin access is tight around the side of the motor.
I'm toying with the idea of changing to a central cabin hatch, but will decide once I see it installed.
The engine reconditioner I've spoken to thinks I will be saving about 100kg in weight.
The engine mounts will take a bit of thought.
The front ones will need steel fabrications using the bolt holes in the block.
The very solid rear ones on the Ford are mounted on the Bell housing that Lees fabricated when they did the marinization.
The Nissan has 4-5 unused bolt holes around the bottom semicircle of the bellhousing.
I'm thinking about a 10mm vertical flat plate picking up those, welded and webbed to some heavy box section across the plate sitting on the engine bearers.
The current setup is solid mounted, but I'm planning to use rubber mounts.
This weekend I'll start stripping the Ford, aiming to get the head off for inspection and final decision on how bad it is.