97, 4.3, 210000 miles ran ruff oil wasnt milky when i drained it cata. Converter is shot alot of black soot on the 02 sensor and in the y pipe on the passenger side my guess is from the converter being plugged. Is it worth rebuilding or get a crate motor any ideas will be helpfull. Thanks

 

Ya see a crate motor has been rebuilt with parts that are within specs. Also depends if you go with the long block.
If you can spec the parts or get that done at a machine shop then you can usually save some cash.