354 truck block oiling

johnny5 · Post by **johnny5** » Sat Nov 11, 2006 2:27 pm

The 354 truck block has a taller rear main cap mount than a car block. Does anyone know if the 392 stock oil pump and drive shaft is a direct swap into the 354 truck block? As an alternative, Can the rear main cap and oil pump from a small block Dodge be used instead?

TrWaters · Post by **TrWaters** » Sat Nov 11, 2006 6:58 pm

The "tall" truck rear main cap has an oil pump mounting pad which is approximately .125 higher than a "car" cap. They also use the wide bolt pattern pump mount which is consistant with those pumps without the screw in pick-up tube. The screw in tube style, i.e., 392 pumps have a narrower bolt pattern.

The use of a late model rear cap and oil pump is not a bolt on. There is a thickness difference between the 331-354 bearing shell and the later 318-340 bearings. Besides the align bore, I dont believe the late oil pump drive shaft is the correct length. The late cap also does not fit over the main cap dowel.

Bailiesdad · Post by **Bailiesdad** » Sat Nov 11, 2006 7:32 pm

"Can the rear main cap and oil pump from a small block Dodge be used instead?"

Nope, not possible.

johnny5 · Post by **johnny5** » Sun Nov 12, 2006 6:38 am

TrWaters wrote:The "tall" truck rear main cap has an oil pump mounting pad which is approximately .125 higher than a "car" cap. They also use the wide bolt pattern pump mount which is consistant with those pumps without the screw in pick-up tube. The screw in tube style, i.e., 392 pumps have a narrower bolt pattern.

The use of a late model rear cap and oil pump is not a bolt on. There is a thickness difference between the 331-354 bearing shell and the later 318-340 bearings. Besides the align bore, I dont believe the late oil pump drive shaft is the correct length. The late cap also does not fit over the main cap dowel.

Thanks for the input. It sounds like the oil pump is the same as the 331 but the cap is taller for some odd reason.

Bailiesdad · Post by **Bailiesdad** » Mon Nov 13, 2006 7:31 pm

"It sounds like the oil pump is the same as the 331 but the cap is taller for some odd reason:

To push the pump down into the back of the full rear sump truck oil pans.