Engine build

[chevycheetah]

I'm starting my build of my '72 I bought in January. I've finally got the money and job security to make it happen, so this is my new toy. I've only removed the intake manifold and the valve covers but what I have seen is not pretty so far at all... The center air passage on the intake manifold is burnt to hell and back and there is a fair amount of carbon build up underneath the intake manifold. Plugging several of the openings under the intake manifold was a mold looking substance that I had never seen before. A mechanic friend told me from the pictures that it was most likely that the previous owner used a lot of starting fluid or ether and it is just a build up of that. The carb is far too oversized as well and I'm sure has been turned up to burn more rich. I'm sure the valves are probably fairly burnt up as well. It appears I'm going to rebuild the entire engine and really check it out and clean it up: I'm mostly interested in looking at the crankshaft. It is not the original engine but a fairly new, low mile, crate motor from Summit; that is what scares me. I will try to get pictures and keep posting updates. Curious what some ideas would be to build up this 350? (assuming the block is in good enough condition)
I don't want anything out of this world, just a nice, properly running engine that can tow a bit if needed on very, very rare occasions. I also know where I can get two 7.3l diesels and a transmission for $800 from a friend of a friend who is a diesel mechanic. Maybe worth checking out?
Not sure what I want to do on the engine yet but I've got to repair the brakes and cab first anyhow so until then, I can plan.