Cam Swap - 318/5.2L Magnum V8 - '65 Barracuda

Want to switch my stock cam out and put an aftermarket cam in a 1996 Dodge 'carbureted' Magnum 318/5.2L V8 that will be making its way into my 1965 Plymouth Barracuda. Shooting for the lopey/thumpy sound, like this Duster has in this video:

[ame="https://www.youtube.com/watch?v=ufRTSVOnmDQ"]Plymouth Duster Hughes Whiplash cam - YouTube[/ame]

I believe I would have to switch my whole valve train up towards a flat-tappet setup to achieve this cam swap, looking for alternatives... Still got a long ways to learn about the define specifics/details of motors measurements and such, got the basics down though! Have experience with small blocks, not rebuilding necessarily, just the typical amateur regasket/reseal/repaint + throw a new timing chain in if needed.

Done a stock 5.2L Magnum Swap into a '65 Valiant 200, and was surprised by the dramatic difference in power vs a stock 2bbl 273. Anyways.. Any help would be greatly appreciated!