I have the Jacobs/Cummins exhaust brake in my 2006 - it was a kit that I purchased from the Dodge dealer a year after I purchased the truck. The brake is vacuum-actuated, and this kit included a vacuum pump that mounts to the engine, a longer serpentine belt, a solenoid, and the plumbing and wiring to fit it all together.
Which makes me curious - what about the Pac Brake installation is interfering with the oil filter? The brake assembly (cast iron elbow with the movable restrictor flap) comes off the back (exhaust side) of the turbocharger, which is behind the oil filter. I'm going to guess that the Pac Brake requires compressed air, as that was typical of the optional Pac Brakes that my (former) employer installed when a customer ordered one. So...is there a compressed air source that some owners are locating forward of the turbo, that's causing interference? Or is there something else?
If my guess that a compressed air source is behind the interference is the case, there's any number of possibilities to consider, including: could an air compressor be mounted to the engine?; could the actuator be changed to a vacuum device to allow operation similar to the Jacobs/Cummins setup?; would converting the truck to a single battery give more space? To that last - there is one supplier of aftermarket battery cables that's developed a single-battery kit for the 3rd Gen Rams for "big turbo" conversions that might work for this.
For what it's worth...I can get the part number of the Cummins vacuum pump, as I had to replace mine back in 2022, if you want to check availability.
