Yeah, it's really odd.
You'd think a blue block would be C8VE, but then it would be internal balance, and depending on the crank, could be a 429.
(no saying Florida Man didn't put an external crank in a lower deck, clearanced block)
The valve covers are grey, so definitely post '82.
What was running that much advance?
Maybe marine, or stationary?
Could the calibration code define it for us?
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.