It's not a pig, it just does not lend itself well to an early A body.
The LA will require some work, too- but it can all be done with existing factory parts. Or just go through the slant like @pishta said- they can be plenty peppy in a light early A.
To give yourself an idea of what's involved in the swap, in the Early A forum, go to the search box and type in something like "63 V8 swap" and you'll have enough reading on the subject to last you the rest of the day...
Such as Search Results for Query: 63 v8 swap | For A Bodies Only Mopar Forum
