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I cant say if cutting the bumpstop brackets off will require engineering. Its not something someone could see has been done if done properly. If you cut them off neatly and fit the wagon stops in there no one will no. I dont recommend doing this if your taking heavy loads. But i havnent had any dramas for the past year and half.
Advice. Save your money for a V8 or I6T.
Valve stem seals, Piston rings, rear main seal and/or housing, timing cover, sump, rocker covers, head gasket.
Check the condition of the spark plugs for a start.
Yeah, not gonna do anything big motor wise, just keep that like it it's is, replace what needed to be replaced an the rest hahaQuoted for truth! Just cruise it, enjoy it for what it is.