[tom s]

Jeff,you can see it in one of the pics of the block,looks like flat tops.Tom

[JSuchma]

Originally Posted by tom s

Jeff,you can see it in one of the pics of the block,looks like flat tops.Tom

Ooooooops.....thanks Tom, I must have missed it!

[Baron Von Zeppelin]

It is an SD block with the lifter bore ribs and big distributor hole , and probably is/was NOS ,
and then someone started building it up.
True they were only fitted blocks over the counter, but not everything always came from over the counter.
Some came through various doors at PMD.

I'm not sure about those connecting rods being SD , or even forged.
The cobwebs in my head thinks they had 12 point nuts on SD rods.
We need some better/clearer pictures and some more input from Chevy Kenny

Pictures of the block face would be very helpful , any stampings you find there , and any evidence or lack of evidence of a timing cover gasket ghost trail.

It doesn't have to be un-run , but that would be a little higher value and more true to NOS.

Surprising that some of us even found this with it being in the 1977 - 1981 section.
It barely caught the corner of my eye

It will service any 73 or 74 SD Formula or TA