AllData shows 4.3 warranty and 5.9 standard labor for the '92 300TE with M103 engine. My tech, who I trust, told me it took him 8 hours the first time. It's buried in there. You should seriously consider the belt tensioner and definitely replace the tensioner shock while in there.

__________________
David
1986 300E Anthracite + ECodes + MB Mileage Award