I own a 1999 bmw 740il. engine broke down
I'd have the same one built by a pro, that way you get warrantee for parts and service.
Are you doing the work yourself? If a shop is, they probably have some connections. Buying a used engine is a crap shoot like you know. Finding one that the owner said it was pulled while running properly is tough being how old the car is now. It's going to take some time. Rebuilding is a good idea on most cars, but on a BMW can be more than the car is worth.
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