Cadillac Repair: 1996 Cadillac Deville Concours 4.6L Northstar, water condensation, head gasket

Question
Hello,a dn thank you for your help. I recently bought a 1996 Deville concours,, $600 Beautiful condition,, unfortunately I believe the head gasket is bad. The symptoms are the car will start and Idle,, But Belches the water out of the Radiator resevoir. it seem to be under a lot of pressure... i.e.,,, exhaust?? it also seem to haev water///??? Condensation comming out of the exhaoust tail pipe,, AND,, it had a Milky apperance in the Oil,, and under the Oil capis a Milky oil mess,,
Really I feel it is a bad head gasket, ,, My question is,, can I do this repair myself? I have built many 350 chevys, have a 57 2dr HT in full frame off restoration,, But am sceeered of pulling this engine,, because of al the bad press, from Mechanic friends... what is your oppinion?  DOable,, or,, Just replace it wih a rebuilt one? If so,, what is interchangeable wiht what??? Mine is a 4.6L Northstar,, not sure of the Vin,, code ,, 9 or Y??  Deville Concours,, I have seen several on ebay,,, but a little leary, of the Common Head Problem wiht these.

Thank you in advance for any and all advice

Jeff

Answer
Buy a rebuilt off of a reputable rebuilder in your area in case you have a problem with it you can take it back. If you buy it off e-bay all they will do is give you another engine but you have to pay the shipping of the new one and the shipping of the old one back to them.