I'm Cummins swapping a '74 Duster, thought I'd share the progress.

You might be able to eventually shove that engine in there and make it run and drive but it will never be “safe” to drive on the road. The amount of structure that will need to be removed will make an already flimsy car even worse. Not to mention the weight bias.
Possibly if you are an expert fabricator you could get it strengthened up enough (frame ties, crossmembers, roll cage, etc) to not be a total death trap but by that time you’ll have a ton of time and money in it. But if that’s what you’re after go for it. That’s hot rodding.
My goal is to remove as little structure as possible and strengthen as I go, I have no idea what I'm doing but I've put allot of thought into this project, been planning it for 3 almost 4 years now. All that's left to do is go for it and problem solve as I go