Big block, clean as heck. LS is a dime a dozen now. I would make a simple BBC, clean up the lines on the body, and document the whole build. Then sell it.
I vote budget build as long as it's nothing special. "Expect to spend at least 30-40k to restore" is something you always hear about project cars. Why not destroy that notion entirely? The spirit of the ls swap is that it is cheap and obtainable for the average Joe. How about going the other direction and just build the cheapest ls swap you can. Set the bar much lower. Many of us would be happy with a simple driver quality car. Can you get this car ls swapped and back on the road for under 15k? Maybe have it as a background project where you only put a couple hundred into it a month. Something that the average person might do.