My sister is needing a new car for her 17 y/o daughter. she asks that if she gets a cheap one if I can wrench on it and make it driveable and safe. Of course I can and will.

She comes across a 2005 Impala with 120k going for 1,000 due to a "head gasket"

I say yes that's the car. Get it. The 3800 is the only motor I have any real experience with (thanks to this website).

CEL says misfire, and I notice it likes to heat up, PERFECT I think, I'll do the LIM gasket and everything and this $3k car will be big, safe, reliable, and at half cost.

4 days later, after messing with it in my free time after work, it has new LIM, UIM gaskets, freshly cleaned manifold and throttle body (they were nasty), new plug wires and of course new oil.
The previous owner already put in new spark plugs but I could tell he really didn't know a thing about cars and the people who worked on it probably didn't either.

I start it up and notice it's still misfiriing. Just gave it a compression test that didn't look good at all -> Shared album - Ian Oliver - Google Photos

Now I'm realizing I may have the one 3800 in the whole state with a bad head gasket. I thought for sure that was impossible. I am a fool in a man's shoes. I should have double checked everything instead of assuming I knew it all.