I know the correct pump is listed as the GSS 340...the only difference I can see between the two is the inlet is a slightly different offset...but not having done this yet on a mustang I dont know how critical the inlet spacing is...on my neon for instance it was critical enough that I couldnt use this pump because it had a canister with a certain inlet location...do foxbody mustangs?...the reason I ask is that I have had this pump sitting around brand new for years unable to use it in any of my cars...I recently picked up a SVO and need to upgrade the fuel pump as part of a process to trace down a high boost issue...since I already have the 341, it would be ideal if I could use it, or at least get it to work with no massive mods