Welcome to CHR Mart1n!
Its been nearly twenty years since we did our engine/trans/suspension swap in our '47 Ford sedan.
We used Jaguar suspension, (don't recall what model, but think it was XJ6,) and it was a straightforward exercise, with everything retained in its original 'cage' and just bolted/welded in.
Initially we used an Oldsmobubble 350 donkey and box, later upgrading to a crate Chev 350/350.
We had to recess the firewall to get it in, so I went to the local Hospice shop and got an oven baking dish, chopped off one end, split it down the middle, folded some panel steel to go between the two halves, welded it in, and that gave us our recess, with nice compound curves in the corners.
The engine/transmission mounts were then built to suit.
As I say, it was quite a while back; but I don't recall any 'major' hassles.
It was all pretty simple.
(Like me . . . I'm pretty simple!)