You have to tell what you want out of the motor, if its the stock 400, Ect. Any compotent engine builder can build a Oldsmobile motor. I have personally rebuilt a 455, a 403 and a 260 Oldsmobile. If you have the machine work done by any shop, you should be able to rebuild it by hand if you have the time, patience and tools. Oh, and congrats on snagging a 442. Their starting to become few and far between.