This is what engine conversions were about in the late 50's to middle 60's.
http://www.flickr.com/photos/k513/4590059133/in/photostream/This image is of a Hurst saddle mount (so named because of the shape) for a SB Chevy (upper) and a 55-65 Pontiac (lower).
The idea was to make another motor fit in a 41-48 Ford chassis as a replacement for a 59A flathead.
The second part of this was to make frame adapters that would emulate the 41-48 Ford frame.
So if you had a 49-53 Ford, you could buy the frame adapters for that chassis and install a 59A V8 (as if you would want) or choose from
from a variety of engine mounts.
I used the pictured SB Chevy mount in both a 50 Ford and a 47 Willys 2WD
Some combinations were not possible - Ford FE (332-352-360-390-428) or Ford 221-260-289 - because of the oil pan.
Some were not likely although they were done. Example the Nail-head Buick V8 in a Ford chassis because the Buick starter was
in the same area as the Ford steering box.
This was an attempt at a "bolt-in" solution using mix 'n match components.
But really, if you spent some time studying the problem, you could come up with a specific design that was more satisfactory for your situation.