I have the intake manifold, its support, the motor mount top bracket, and the accessory bracket off my 1990 745 GL B230F engine at the present time. This car has 180k miles and has never had preventive maintenance other than regular oil changes from PO, so I am replacing old brittle gaskets and o-rings by the handful here as I clean out the flame trap, oil breather box, egr system, replace worn-out accessory bushings, replace collapsed motor mounts, and remove years of greasy, sandy muck from unattended oil leaks and no belly pan.

While removing the oily sludge from the driver's side of the block I unburied a shiny plated (not red)football shaped cover plate held in place by 2 flange-head bolts. The plate is located roughly in the center of the block between cylinders 1 and 2. It is roughly at the same altitude, but to the right of the the plugged boss that would hold the distributor on a 240. I have linked a library photo of a raw block that shows the uncovered port surrounded by orange. From the photo it would seem that an orange paper gasket may be used.

The left bolt on my car holds a stainless steel clip for the A/C compressor clutch connector. The right bolt holds a rubber lined steel wire harness strap holding the main wire harness for knock sensor,fuel injectors, etc. in place. I removed the right bolt to release the wire harness, but I am afraid to remove the left bolt not having a gasket or o-ring at hand to re-seal the plate. I have so far just removed the left bolt and then the right bolt one at a time to avoid breaking the seal. I would ordinarily remove the plate, replace the gasket with a new one, and button it up, but I don't even know what the plate is covering up.

Is this cover plate where one would install a bolt-on block heater if one didn't live in California? If so, then I presume that there is antifreeze on the other side of the plate. Does this plate use a paper gasket or an o-ring? Can anyone help me with a part number for a replacement gasket/o-ring?