How to tell if head fit my 87 325is

[bobome]

We got a head off a 1986 325 at the junk yard. I got it cleaned, pressure tested, and valve job from a machine shop, only to learn it was the wrong head for my 1987 325is because the pistons was hitting against the head. My 87 325is had a bigger slope therefore the pistons wasn't hitting the head. My questions are-how many versions or models does BMW made for the E30 engine? And how do you tell if the head is right for your engine. This is a very expensive and disappointing experience. Please share your knowledge hopefully someone can learn from this and will not make the same mistake I made. Thank you.

[Jeron]

Use realoem.com

Put in your VIN and get the part number for your head then look at other models and years to see which have the same part. That may yield a group that is too narrow but it should get you started.

[bobome]

I looked in RealOEM.com, searched the part number on pelicanparts.com but no cylinder head came up, just parts. I noticed there's a 7-digit number on every head, does that must anything? Must I find the exact number to fit my engine? My old cylinder head got #1705885. The replacement that doesn't fit got #1264200. Does these numbers tell you what model it came from? Thank you for your advice.

[Jeron]

The part number for the head is in realoem.com. Compare that part number to the head part number of the other models you find to get compatible models.

The only meaningful marking on my head is SB A 53927. The only other marks are the VIN and several dates.