Oil pressure relief valve seat.......agayne......

[bwaminispeed]

Do the early 850 blocks have removable steel relief valve seats, or, we're some just drilled/machined into the cast iron of the block.....

Got one that is being rather stubborn at coming out of the block.......

[Spider]

I'm sure it would have had a pressed in seat. You can check if you have the main oil gallery plugs pulled, put a torch up to one of them and see if you can see any light when you look down the oilway to no.3 Main Bearing. You'll see it through nos. 1 and 2 but it should be dark when looking through no. 3.

[Oneball]

There has to be a removable seat doesn’t there as its waisted shape seals the main gallery as well as acting as a seat.