I will ramble a little.
I am speaking from experience, not hearsay. I have built many high dollar SBC's. It cost big money to build one that will last with big power #s(800-1000 hp). I also used to be in the buisness of selling used LS1's. I have sold them for profit for as much as $3500 and as little as $2400 turnkey. I bought them for far less, you just have to keep an eye open, but that is besides the point.
I am not saying big power cannot be made with a sbc. Heck there are 2000 hp SBC's.They can make equal power, but not at the same cost for the 1000 hp level.
The reason i went to an LS1 last year is I wanted a turbo setup. The "bullet proof" motor I had, plus the turbos would have been too much money and I was already afraid of hurting the engine. I was able to buy an LS1, build it, and twin turbo it for the cost I sold my N/A motor for!! That is why I did not turbo the SBC.
I like the huge weight off my chest knowing if I hurt this motor, they are a dime a dozen, for instance, I break a rod and take out a block and crank. An LS1 block and crank can be had for $500, where as a sbc aftermarket block and crank to handle this power would cost about $3200.
I am now really PRO-LS1 because of the basic reasons of, low cost, fuel injected driveability and mileage, and the aluminum block!! I think the aluminum block is the best part, I always wanted one, but at $3500+ for a aluminum dart block, I could not afford that in my whole life!
Also, the rating on the ls1's is a little low. Stock ls1's are dynoing 350 rwhp. That is what they are rated at at the crank, I don't know what is up with that, but they make much more at the crank then they advertise.
Again, I love SBC's, I have alway stuck by them, but since I went LS1 and had such huge luck with power and low cost, I personally would never go back. I built a ls1 that will handle 1000+ hp for only $5500, That is just too cheap!!
Yes, I have turned into a tightwad!