I think the block number you posted has too many 4's.
Check to see if it isn't 14015445. 14015445, 454, 78-90, 2 or 4 bolt

The heads appear to be 346236, 75-87, oval, OPEN, 454, 120cc chamber, 225/116cc ports
I believe those are the so-called "peanut port heads" with large open chambers. Compression ratio with a flat-top piston should be 8:1 or so.

I'm really a bit out of my depth here, but that's what I was able to find.