I have a 2001 Dodge Ram 1500, my vent hose on the Rear end Housing was stopped up. While clearing it I noticed a electrical plug in on top of the rear end with a wire running to it, any idea what it is?

Also my truck had a 318 in it I swapped it out for a new 360, with the 318 I did not need exhaust gaskets but since I installed the 360 I have to use exhaust gaskets or it will leak. Is there a difference 318 and 360 exhaust manifolds?

Thanks for your time

 

rear abs sensor. aka rear diff speed sensor (not to be confused with the transmission speed sensor).

manifold difference - i don't think so. almost all parts are interchangeable except harmonic balancer and torque converter.

 

Mr. D is correct. Very little difference in external engine components.

From the factory, they have nice machined surfaces to work with, and a lot of them don't use gaskets at all. After a 100K miles or so..... well, they ain't so nice any more, and gaskets are pretty much a requirement.