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HMR 12MM 3.9L 4BT Cummins Cylinder Head Stud Kit

12mm Std Head stud kit for the 3.9L 4BT Cummins Turbo Diesel

 Recommended for applications of 80 psi boost and under with single charger and no drugs.

The head bolt holes in the cummins blocks are not tapped to the bottom.  We have designed these studs with more threads for less stress to the block as well as the stud.  You will need a 12mm x 1.75 bottoming tap.  If you do not have one, we have them for sale.

•12mm, 1722 alloy

•Hex head for easy installation

•Hd washers and 12pt hardened nuts

•Assembly lube


All kits include studs, nuts, 12pt nuts, assembly lube and instructions.

If you want to bottom tap your block before stud installation, the tap you need is M12mm 1.75.

These studs DO NOT require machining the rockers for proper clearance. They are full length and only some grinding on the valve cover is needed.

Picture For Representation Only....

Part# 4BTA112MM

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