Here’s what I find “interesting” about the numbers at the front/rear of the adjoining cylinders.

How do those areas between the cylinders not agree with each other?
Particularly between 4&6 and 3&5.
Is it not a Siamese block?

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads