Dinan muffler and intake from a 4.4 to the 4.8?
 

Anyone know if these parts are interchangeable from a 4.4 to 4.8is? Thanks!

Should be a pretty easy fabrication to make it work on a 4.8is. you will proably need to cut off old mufflers that attach to the center resonator and use the mounting flangs with pipe to connet to the Dinan 4.4 mufflers. I cane across a killer deal on a set of new Eisenman race exhaust for a 4.4 and i purchased them and had a muffler shop cut off a section of the pipe that mounts to the center resonator and connect them to Eisenman and then hook them up to my 4.6is X5.

Well what I'm afraid of is that the piping is too small in diameter.. Even if I adapted it to the 4.8 piping, it'll be going from big to small piping. I know dinan had a different part number between the 2 engines.

center resonator between 4.4. and 4.8is differ. My flanges for connecting the eisenmann was different than the 4.6is flanges so I cut them off and re-welded them back in on the Eisenmann. Pipe diamter was the same.