Perspective: Considering the economic reality of most of our board members what is the effective difference between a mild (4bbl + headers) 318 and a 360? ... 75hp? And it gets even closer if you're considering properly matched heads and cam on either motor. That $3k is technically better spent on a "chinese ebay turbo", intercooler, piping, a blow through carb, and fuel upgrades.
And before you think I'm saying "Well you should just spend $7k on a hot built crate", No...
If you're thinking of spending money because you want some real power the purely logical decision is to turn the old Mopar sexy noisemaker into a coffee table and pull a junkyard Vortec V8, a 4L80e, and a modified Ford Explorer rear axle. That sloppy combo supports nearly 1000hp worth of boost in stock form. That's enough to twist your unibody so hard you'll blow your OWN doors off.
But most of us are more theatrical/sentimental than actually power hungry. Leading me to the moral of the story...
Build what you have, as well as you can afford, and don't compromise too much driveability/enjoyment for power. You know the old saying "There's always someone faster?" Well it's almost 2019, turbos got cheap, and friggin EVERYONE is faster.