: exhaust for 4.4L-4.6L

12-15-12, 01:04 PM
hey guys just looking around on ebay for an axle back exhaust for my 05 sts with a 4.6 and having alot easier of a time finding one for a 4.4L would you think they are the same?

12-15-12, 06:56 PM
I cannot comment on whether it is the same or not, but if I recall correctly, the 4.4L is the same block as the 4.6, but thicker cylinder walls to accomodate the added pressure.

12-15-12, 07:04 PM
Nope. The STS-V exhaust pipes (4.4L) are wider then N* pipes. I've had a muffler shop weld the Gibson axle backs onto my N*. I'd say he had to fill a 1/8" gap all around. At the time I didn't know that there was going to be a gap, but so far-so good - the exhaust sounds awesome! Long story short - there is a difference but, if you have someone weld the exhaust together it can still work.

12-15-12, 08:34 PM
i could just expand the pipe then if its 1/8 around the whole pipe. your just meaning that the cars pipe was smaller than the gibson ones right?

12-17-12, 10:32 PM
aliskerov, do you know if it is the same off the cats? Do both cars use the same cats? If the blocks are the same (which I think they are)it seems it would be reasonable to assume the cats are the same. And maybe it opens up more at the rear for the V.

12-17-12, 10:57 PM
Apparently they use the same manifolds so I'm sure the cats are the same

Charles Warren
12-19-12, 05:24 AM
2.25 vs 2.5