I too planned to have a stand by motor but later realized, I know the existing motor and the worst it can have is a blown head gasket. It is better to get factory parts and to get it done right (with proper head job including valve guides/seals etc.,). With all these I am sure one can run the engine for another 200K miles easily.
Remanufactured motors are OK, but the parts they use are not factory toyota parts so the engine may wear out in 100 K miles.
Remanufactured motors are OK, but the parts they use are not factory toyota parts so the engine may wear out in 100 K miles.