How THE HELL...
For more help, try bigblock dart website.
http://bigblockdart.com/
I saw a 361 being Put into a 1966 Valiant, in 1977.
It was a not easy project.
I was going to Midland, TX. Community College at the time.
I never did see the car run, under the big blocks power. Nor sure how it ended up, in the long run.
A big small block would be easier.