Brand new magnaflow Y-pipe/cat part number MGN 93312 doesn't fit...1992 f150 custom 5.8l

The old flanges are 2.75 and the new are more like 2.5". it seems like they are in a slightly different position too.

as far as I can tell casting numbers are RF-E8TE-9481-AB for driver's side and RF-E8TE-9480-AB for passenger side...HELP!

 

It would not be the first time someone put a y-pipe for a 5.0L in the 5.8L box or vice versa. The different positions and smaller size is the smoking gun evidence here.......I had the same type problem when I purchased my Bassani Y-pipe. The box was labeled for a 5.8L engine but the part inside would clearly not fit, it was a 5.0L version!

 

Are you sure they don't fit? That is the right part number for the 5.8 and the flange IS supposed to be 2.5", not 2.75". The one for the 5.0 is 2" so you don't have the wrong part. Every parts place I check lists that part with those dimensions and they are all the same part number everywhere...

 

Trust me, it doesnt fit. The two downpipes aee about 2.5" and 20 degrees off. Looks like tgey f#$ked up the jig for a while starting around april. Looks like i got one of those

 

Anyway to persuade it? Heat? Violent beating?

 

I'm not saying your wrong, you would know better than I would. Unfortunately that is the part that is listed everywhere as fitting... Are your manifolds stock? Or are they shorty headers?

 

I had a similar problem with my Magnaflow y-pipe. I assumed it was due to my shorty headers. But the flange was only off on the driver's side, passenger side fit no problem.

 

I went and measuers the distance bewtween downpipes at ~20". It looks like they sent me an obviously wrong part. It doesn't even look like it's for this family of engines. The pic on their site of the one for the 5.0 (5.8 has no dimensions) shows this measurement at 21.5" and the 5.8 should be slightly wider. I'll be talking to RockAuto today and try and get them to ship one out and pay for shipping back...If they won't can someone recommend a good parts house?

 

Anyone have any insight to the casting numbers?

 

I talked with a magnaflow rep and he's getting some measurements so I can confirm what part I got. He said that every so often (mid year, etc) a truck gets put together differently. and that maybe mine was such. he also said in 16,000 units sold only 4 were returned for fitment issues.

how can I determine if my truck has stock exhaust manifolds or not? what should the flange size be? what else should tell me? anyone have pictures of stock manifolds?

 

I have a feeling the low return rate is because it's cheaper to modify the part to fit than it is to return it, especially if your truck is out of commission while waiting for a replacment part.

 

I'm waving the BS flag. Ford has used the same exhaust manifolds on these trucks for years with no changes. Plain and simple they put the wrong part in the box or it was made wrong.

Look at the photos in the first post on this thread: http://fullsizebronco.com/forum/showthread.php?t=40279 It shows pics of the 5.8L Bassani y-pipe and the 5.0L version. You can see the down pipe angle differences between the two. As well as size.....

 

Good news is rockauto will be paying the return postage! so if nothing else, i'll get refunded my money and purchase either the correct mangaflow unit or something else...

 

and after looking at that link, i'm more convinced than ever that they sent me a misboxed part...

 

Rockauto is great to deal with. I have always had great prices and service!