Cadillac Repair: 91 deville Pass key, blown head gasket, head gasket leak

Question
I just bought a 91 sedan deville FWD 4.9. the lady i bought it off of lost thr round key, and i looked the doors by accenet. It took 3 days but i finaly got in with a coat hanger. Anyways  there is now a problem with the ignition key. I would like to bypass it. How do i find out what resister to wire in. Also I would like  to know what are the common problems with this car
200,000K.

Thanks. Darryl

Answer
No way to bypass this to my knowledge, except by theory leaving the battery disconnected for a prolonged period of time(mor than 2 hours)
Common problems
Air compressor blown
Head gasket leak
Suspension bottoms out
Oil pan leak
Misfires, misfires, misfires,
Rusted cooling system
Blocked heater core
Vacuum leaks
Hub and bearing assembly and worn CV joints,
All deville transmissions can take a hell of a beating but i still had to rebuild mine at 130,000 miles, and replace the motor mounts which i would NOT reccomend doing yourself unless you have an engine hoist, in which case remove the engine and then put the mounts on, it may seem like more work but trust me removing the engine is in fact easier then tryin to replace the mounts while its mounted.

Avg Cosmetic damage, worn paint, leather, headliner, etc...
worn cam lobes although this is extremely rare ive seen it on a couple of ht-4100s, only twice on a 4.5, and never on a 4.9...