Thought I'd bump this because I'm interested as well.
My exhaust has had some issues so when I fix them I want it done right.
I thought the stock over axle pipes were 2.25" ID but they are 2.25" OD, my mistake I guess. I put in 2.25" ID glasspacks and they fit over the stock piping. Which would be fine to weld but I just have them clamped.
So now since I have the BBK Shorties, MRT H-pipe, and Borla S-types, I'd like to make the entire exhaust 2.5". If I get these over axle pipes, how will they mate up to the mid pipe? I assume the mid pipe must come down to 2.25" to mate up to the stock piping. And I'm guessing the borla axle backs are 2.25" also?
I'm disappointed because even though I got the sound I was after, leaks and sizing issues have caused it to turn into a bit of a money pit.
a mustang is the definition of a money pit.
my bbk mid pipe was made to hook up to the stock overaxle pipes so the mid pipe ends with 2.25. the dynamax pipes start out with 2.25 (same as the ending of the bbk midpipe) so the shop reused the stock clamp.
As for the muffler side of these pipes, they end with 2.5 so i had the shop cut and weld the stock pipe ball joint fittings to the dynamax pipes. so i can still take my mufflers off and stuff.