2000 STS, N*interchangibility?

Whats wrong with the original motor? I know you said the HG's were gone so if it were me I would repair the motor using Jake's studs and get all the seals and other parts fixed and drive it till the wheels fell off. While used motors seem like a good deal, putting a new used engine in with old electronics and other systems don't turn out so well most of the time. N* are extremely picky, and there is a possibility a used motor will end up with a HG problem down the road as well.

I'm not the know it all Northstar guy around here, but from what I've seen most engine swaps do not end up well. It really all depends on what you want to get out of the car. However if it were me I would just keep the original motor and get the headgasket replaced.

My headgaskets went at 54k miles and they replace those, timeserted the motor, re-did all the seals, new motor mount, and quite a few other things. I've put another 16k on the motor and haven't experienced any trouble with the car since then.

Yup all twenty holes have to be timeserted, which requires the motor to be taken out of the car; normal cost at dealer would be around $3500. Most dealerships also do the water pumps, seals, motor mounts, etc. which would come out to around $5k for a complete overhaul. That's what was done to mine.

Jake does the whole shebang for around $1500 (+/-) and can also do other things for half or 3/4ths the cost the Caddy dealer would charge.

In 2003 they changed the size and type of bolt used (I believe one similar to what GM uses in the LS1) and so far very few failures have happened. However, the older these cars get the more failures you see pop up. Two years ago the '97-'99's were failing every day while the 2000-2003's had little to few problems. It seems that once these cars hit about 8 years old, they tend to start giving the owners problems.