Welcome to the site Joel. It sounds like you have an interesting project that you will be starting and we would like to help, if at all possible. Pictures - we really like them and do well with answering your questions as there are many here with extremely high levels of talent.

Now - the frame. I think the first thing you have to do is draw up a "plan" on what you want to do with this car and what you want it to look like when done. This is a long term project, months occasionally and years usually .... and it does cost a lot of money as well as time. There was a time when the local salvage yard had all you needed for a reasonable price - those days are for the most part, gone.

Back to the frame. I would first crawl around under the car, checking for rust out or very heavy pitting. If it's OK, then pull the body off and do a more thorough check. Cross members are often cracked, not a big deal as after market pieces are available. Frame side rails often have cracks at some of the many holes - this may or may not be a problem depending on how bad, but these can be repaired and strengthened with boxing.

If the frame is "junk" then you have two directions - an after market frame from someone like TCI or Speedway, or weld up your own.

OK - something more to think about - engine/transmission and the rest of the drive line. Of course, the front axle, brakes, etc, etc, etc. And I have to say, SB Chevy power isn't the only way to go

Let us know how you make out