Haha, love waking the neighbors. My neighbor behind us has a 350 in his Tempest that was rebuilt a couple years ago, and I don't think he has anything special for exhaust either; and I can usually hear him start it up in the garage. I think ours is fairly loud (it does have some old cherry bombs), but not bad. Never had any complaints anyway.

Yeah, I'm back to 10W30. The first time I drove it to work this year (30 miles highway) I ran it really low on the way home. Found out I was about 3 quarts low. Still don't know how it happened. I can't recall if I checked it before then, but I check it pretty regular and haven't had a problem before. So I wondered if I had a blowout of oil somehow (it still had the 20-50 oil). I changed back to 30 weight, and so far so good.

And yes, the cowl tag is pretty much directly over the master cylinder.

Grimm--

Thanks for the decoding. Hopefully you can make out all of the info. with both pictures.
At this point, all I know is that it'* a 87 Series Holiday Coupe (336"87"). Can you tell me the interior color? I've seen three different blues and I'm curious to see which one I have when I order restoration parts. Thanks.

Top line: First sequence is month and week. So 04 is April; and B is the second week.
I don't know what the remaining top numbers mean.
Second line: 68 is the year of course. 33687 is Oldsmobile (3), Cutlass * (36) and Holiday Coupe (87). BFXXXXXX is the plant and unit number. BF is for Fremont California.
Third line: 953 is the seat type/color. I'll have to check that when I get home. No mention of what B80 is, but the consensus I found recently is that is refers to the chrome drip rails. The DD is the paint color. The first letter is the bottom, and the second letter is the top (different for vinyl, convertible, or a few rare coupes with a different color paint). The name of the color is Sapphire Blue Poly.

The 953 is a Blue split bench seat. I see suppliers list a medium and light blue, so I'm not sure what you would be after. Turqoise is the other blue type color.