It's good to see some more pics of your most recent acquisition.
That tach sure doies look original, but I have not seen an original that went to 8K
The suffix code stamped on the pad in front of the passenger side head will tel you what the engine is. That harmonic balancer is not typical of the early 327, let alone a 283, of the lower HP ratings.
I'm really curious to see some pics of the auxiliary trans.