Valve Seat Insert Compatible With 1980-1992 John Deere 3050/3055/3140/3150 300 Series 6-Cyl Diesel

JOHN DEERE TRACTORS:
• John Deere 2940/2950/2955/3040/3050/3055/... 300 Series 5.9L Diesel (1980-1992)


IMPORTANT:
This is a .002" (.05mm) OVERSIZE intake valve SEAT INSERT for John Deere 300 Series engines (6.329/6.359, 5.9L, 6-cylinder). This is NOT a valve — it is a seat insert that presses into the cylinder head. The .002" oversize has a slightly larger outside diameter than standard for heads where the seat bore has been machined/recut to oversize during a rebuild. If your head has standard-size seat bores (not recut), do NOT order this insert — you need a standard-size seat insert instead. Confusing seat inserts with valves, or ordering standard vs oversize, are the two most common mistakes with this part.

Fits JD 300 Series engines in 2940/2950/2955/3040/3050/3055/3140/3150/3155 tractors (1980-1992). Seat inserts are interference-fit into the cylinder head — installation requires chilling the insert and/or heating the head per the service manual. After installation, the seat face must be cut to the correct angle and width. Always replace valves and stem seals when installing new seat inserts. Measure valve protrusion after final seat cutting.

⚠️ .002" OVERSIZE seat INSERT (not a valve). Confirm head bores are recut to oversize.