Well I was able to get home unexpectedly for a few hours before I'm on the road again to phoenix tomorrow and Friday... Out of curiosity I scraped down the pad on the passenger side of the engine block to see what I could decipher about the motor(wondering if it was original). Here's what I found, don't mind the 1/2" thick sludge build up
If I'm doing it right it seems to break down as a flint built 9/20 1973 4bbl manual trans ls9 350 out of a c/20 or c/30... Close to original but no cigar....