Why buy a engine for $500? Just go buy a rotted in half silverado for same or less or even free. Thats not a unicorn that’s commonplace around here. Then you have pretty much everything and then some to get going. My 4.8 engine i bought Complete in a truck for like $300. I scrapped the cats and sold the trans and it paid for itself. That engine had 200k on it and ran like a absolute top. It ended up making 535hp/600tq with some boost and a set of valve springs. Stock everything else. Oh and that was put through a saginaw 4 speed that everyone called “junk” hahahahahhaha. I swear we live in a constant cycle of old guys repeating the same dumb things that they heard from some guy that new a guy that said his uncles didn’t work but they never actually did anything themselves.

I can in fact LS swap things in a weekend or 2. Its been done with planning and having parts hanging around to test or modify.
I pulled the old flathead V8 out of my ‘41 ford truck and had a LS permanently mounted in place and wired ready to fire in a few weekends. While working a full time 40hr job. No its not gonna do itself. Gotta put the work in.