I have a 2004 F-150 with a build date of 02/04. This afternoon I ordered a 16612 system, and now see that there is a part number of 15821 for these built before May 31st. Can someone tell me the difference between the two and If the 16612 will work? Thanks in advance for all your help.

 

I just checked and my box for the 16612 kit says on the sticker "16612/15821 kits" so I think they are the same. There is a different length midpipe but both are included.

 

New to the forum... Just the topic I want to discuss. I too have an 04 F150. (FX4 Supercrew) I saw both kits 16612 and 15821 available from many distributors.

Here's what I know. I called Magnaflow and they confirmed that 15821 is an older kit. It's no longer in their system and they don't have any information on it anymore. They suggest to go with the 16612 kit. However, the 15821 kit is significantly selling for much cheaper.

I was able to download two pics of each kit from an internet distributor.





It looks very much different from each other. Can anyone confirm the difference in parts between the two kits?

 

Yes the 15821 is just an older part # kit.