512 Block

[RC1]

Hi guys I am new here, figured you guys might know and have the most interest in this block.
It's an A 19 71 casting, 3963512 4-bolt block. Can I assume this is a 71 365HP or 425HP casting? I am looking at selling it rather than using it anymore for my own needs. I'd rather see someone who needs it use it, I'll probably buy an aftermarket block rather than use this for my new build. I'm going to put it in the For Sale section, but just want to verify it's original use. Unfortunately it has been decked, so stampings are gone. Can you guys give me a little guidance on possible value? Thanks, Rick.

 

[73shark]

Welcome to the CAC. Is there a date code on the casting? Is there a stamped number on the psgr side front of the block on the head surface?

 

[RC1]

A 19 71 is the date code, but as I said, it's been decked, so no stamping. I will have some pics up shortly, once the engine's out. Thanks.

 

[Vettehead Mikey]

That's the correct casting number for a '71 BB, either LS5 or LS6

 

[RC1]

It is a 4 bolt though with the large tapped holes at the oil filter pad.

 

[JohnZ]

It is a 4 bolt though with the large tapped holes at the oil filter pad.

That's the correct configuration for a 1971 LS6.

 

[RC1]

That's what I'm kind of hoping, but I'll have a clearer view when I take it out of my car tomorrow.