Before tearing the engine apart, I put some oil in #2 cylinder and re-ran the compression test - it showed 100 psi. Better than the prior reading of 75, but not convincing me that all the compression is getting by the rings.
Then we took it apart.
As BP said, the engine appears quite fixable. We had a little trouble removing the bent valves until BP "straigtened" them. The coil spring compressor was not able to get a good grip on the spring until he took a piece of wood and a hammer to straighten the valve head most of the way. One of them actually broke off.
Interesting that two of the valves were not magnetic - I doubt they were aluminum but there was definitely no iron in them. Maybe this was a prototype...
A couple of holes for cam tower bolts are stripped and probably need helicoil.
Parts list: (edit - current as of 10/14)
1991 Olds Calais - 176.00 bought
Timing chain - 32.85 bought
Head gasket - 26.49 bought
2 valves + alt belt - 28.59 bought
2 valves + head bolts - 31.77 bought
tensioner - 30.75 bought
another intake valve - 7.18 bought
subtotal:
333.63
another exh valve + heli coil - 13.76
threaded rod to for cam tower - 4.22
temp tag - 10.50
rod bearings, oil, filter, spark plugs - 56.24
subtotal:
418.35 (as of 1/1/07)
insurance also running about $20/month
To buy
Spark plugs - the old ones look fairly well rounded
Nitrous kit - 75 HP shot
4 new valves - 40.00 (estimate) Autozone says $5 each but somehow I doubt this
Alternator belt - the old one is separating in the grooves
Thermostat gasket - in stock. I also have a front seal and a few of the other gaskets from a past job so we'll save a few $ there.
To do:
Fix the tensioner - this may cost extra money.
Lap in the new valves
Lap in valves on cyl#2 as it shows 75 psi (100 psi after adding oil in the cylinder). This is to clean off the surfaces and make sure valves are not off just a little
Put it all back together