Help identifying oddball GM Head Casting # 14094171-A

[kaptainkw]

Good day everyone and Happy New Year to you!

I'm hoping the braintrust can provide me an answer. I have come across a pair of NOS aluminum heads, one has the typical #651 casting the other is #14094171-A (yes "-A"). While the holes line-up with the #651, the casting is definitely different and has an "88" casting marking on the top. When I had a machinist do a valve job on them he said the #171-A was "way-off" and I'm concerned that I or someone else would have a problem installing it. I've done an extensive search on the internet and contacted a couple machine shops but nothing turns up.

Anybody have any ideas?

Not that it matters but the car they are associated with is an 1987 Olds Cutlass Cierra 2.8L.

[86euro]

What are the visual differences and what was "way off" according to the machinist?

Can't say I've ever paid a lick of attention to the casting numbers on the gen2 heads. I just assumed they were all interchangeable and I've never had issues from interchanging them either.