Injector Adapter Sleeve 9mm to 7mm - 1988-1991.5 Dodge Cummins 5.9L 12V 3919358

Part # 3919358

This Injector Adapter Sleeve converts the later style 7mm Injector tip to fit into 9mm cylinder head bore. (1) per injector required. Works with 6BT3.9, 6BTA3.9, 4BT3.9 and 4BTA3.9 Cummins engines.

Starting in 1990, cylinder heads for Cummins B Series engines were changed to accept a 7mm tip instead of a 9mm tip. The change was made to increase the material in the head and reduce the incidences of the head cracking. When this change was made, Cummins announced only 7mm injectors would be available after the supply of 9mm injectors ran out. We offer this adapter sleeve to accommodate the 7mm injector in the 9mm head.

The 3919358 Adapter Sleeve effectively allows the new style 7mm tip to fit perfectly into the 9mm bore. It also acts as a sealing washer, sealing the injector bore joint. We recommend replacing the adapter whenever the injector is removed to ensure a new seal each time the injector is installed.