OK, The purchase has been made.
Block casting # 10243880 it is an 880 block
It is an 880 block.typically shown to be a roller block.
The engine came out of a '93 GMC 1500, but most sites list this block as
being used from 95 to 2000, but other sites sat from 87 to ???
Date code A307 so, 1997 ?? 1987 ??
Most say either L31 Vortec or ZZ4 crate motor.
I have seen it listed as being used in a few 95 trucks w/TBI.
My motor has TBI and swirl port heads.
Unsure if 2 bolt or 4 as of yet, and do not yet know if roller cam.
The mechanical fuel pump mounting site has a plate w/4 attaching bolts,
so here's hoping it is mechanical fuel pump ready.
For now, I have to get it out of the back of my truck, pressure wash and put on the stand.
Then the fun will commence.............
Engine block IS machined for mechanical FP !! YEEHAW !!
Serial # is a mystery,tho....... on a sticker on block in front of pass side head: U621xxxx
Another mystery..........