OK, all that sounds fair enough. I never found the SBC to be more prone to leak oil versus anything else, and all that 'perfected' LS stuff came from the previous small block Chevy programs. HEI ignition runs without trauma or even.. maintenance ..for decades. I've seen aftermarket parts vendors fix more than one factory foible over the years (not related to any one specific engine, mind you) so I don't buy the "5000x more engineering" than any aftermarket parts, line of reasoning. The LS hasn't been around as long as the entire world has been making stuff for the small block. I feel like it's a pretty well sorted out unit, at this point.
I guess it's a 'buy once, cry once' deal after you get past the initial expense of the swap... No LS swap guy has ever admitted to paying more than $500 bucks for an LS, so I decided to run down this mythical cheap powerplant. This was the reasonable option for a new one: https://www.speedwaymotors.com/LS-Gen-III-6-0L-Crate-Engine-Kit-364HP-450TQ-Trans-Control,586516.html?utm_matchtype={match_type}&msclkid=20582cb0a6f213fba97a451625b42f42 Over nine grand, and that doesn't include ECU, exhaust, fuel, ignition, etc. that you'd need.
Well that is pretty far from $500, but it looks like I could get a warranted used one starting at $2200 from these guys..
https://603autosalvage.com/used-6-0-ls-engine-for-sale/ Which seems a lot better, however they don't mention if that includes the ECU and wiring, however it might or might not include the intake, fuel rails, and maybe the accessory drive.
For those interested in doing this swap (including myself, since 'LS for Everything' seems to be a thing these days) the 603 Auto Salvage website paints an accurate picture.. You aren't gonna spend $500 and have an LS rig in two weekends. It's not a trivial swap operation-far more complex than my Cadi V8 engine swap, and that was a pretty straight, old GM to old GM switch up. Of course, back then there was almost nothing available pre-made to do what I did, so I had to make every expensive mistake I could make along the way..
But anyway.. to answer the OP's question about exhaust manifolds for an LS into '60-66 Chevy truck, you can buy them here for $400:
https://www.lmctruck.com/mechanical/engine-swap-parts/cbe-1960-66-ls-series-swap-exhaust-manifolds. I'd go cast iron whenever possible versus headers. Longer life, fewer leaks, won't rust out. The above mentioned units also support up to 500HP.
Continuing down tonight's ADHD rabbit hole.. Holley offers a whole bunch of.. all you'll need to stick an LS into the ole' 60-66:
https://www.holley.com/platform/chevrolet/c10-pickup/1960-1966/engine/ls-swap/ It won't be $500.. but it will bolt in, and someone's already done the homework for us :-) Shewwwt, I'm kinda selling myself on this plan! Well, except for the part where I don't have the money, and 417lbs/ft at 4100 RPM just isn't the same as 550lbs/ft of 500cid Cadillac V8 twist at 2600 RPM, in a 15,000lb school bus.
So I guess it comes down the the old adage.. money, time, skills. If you've got the money, you can get it done pretty fast. If you don't have the money, you could take more time and find that unicorn $500 6.0L LS out of a wrecked pickup, and in come the skills to build all the brackets and mounts and adaptions yourself. Super rewarding.. but plan on the above mentioned three years of Sundays before your first night out in it. :-) It sounds like a great idea, but after the engine you'll probably want a more modern gearbox behind it, so there's that to consider.
