What can a sbc do better than a ls. I can't think of anything.

Microwave popcorn or hot air, ls if you want to drive it sb 400 if you want to work on it.

With this build an LS seems like a no brainier. When I bought my engine 3 years ago, I went with a TPI/SBC (tune port) for a few reasons:
1. I wanted fuel injection without breaking the bank.
2. The price of a used LS engine was considerably higher than a TPI SBC
3. I had to be able to find headers to fit without them being a $2000 custom set.
4. The difference in price for the wiring harness and computer from SBC to LS was considerable.

Today, none of these are issues. Everything is available and priced the same. I gave $1100 for a running TPI engine out of a Vette. You can find a good running LS for that now.
The headers, for my car (a 77 Impala, Project Impulse) are still not available and probably will not ever be. For a 1st or second gen Camaro, they are available all day long.

When the LS was introduced, it was dubbed "the next 50 year engine". The SBC was a 50 year engine. So the question becomes, do you want an engine designed for the next 50 years or the last 50 years.

Last thoughts, pull the pan on a SBC and an LS. Take one look at the main caps and see what you think. The LS engines are designed throughout to run higher power, and still remain reliable and streetable for 100G miles or better.

my 2 cents... I spent a lifetime supporting the SBC... absolutely love the engine... and after much internal dialog i am going LS...

Now if an aluminum block Gen1 SBC were affordable i would be leaning in that direction... 18 degree, hell yeah... but since that is cost prohibitive compared to the LS... its LS all the way for me...

if you want around 500 HP or below and money is tight SBC is the way to go...