I received my eBay bought cylinder head today - slightly different cast number and it says 280 S/A instead of 250A- which is stamped on mine. But all the passages are the same, everything looks the same except for the cylinders. On mine the cylinders are cupped out a little bit and on the new one I just got the cylinder head is flat around the cylinders/valves resulting in lowered cylinder capacity in cc's.

I called Mike Elias at Metric Motors and he was very helpful. I gave him the casting numbers and he said the heads were interchangeable, but I am wondering at how big a difference this will have on my block. If I am understanding all of this, lowered cylinder capacity means the engine will now be running at higher compression - is that right? Or do I have it backwards? And if so, what are the risks to the old pistons etc.?

The head looks like it is in very good shape - I measured the height in several places all reading about 85 mm - which is what it is from the factory when new. I think I have plenty of stock. There is some corrosion around some water passages between a couple of the cylinders, so I am a little concerned about that.

I still need a set of cam towers (still hoping the eBay seller comes through, but...). Mike had a set for $180 but I sure would like to find a cheaper set - I only paid $50 for the head.

If anyone has a set, let me know. I don't think I can reuse my old ones...

Ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE