GT mufflers---whats the difference?

Steve McGreen · 07-16-2008

Today I learned there is a difference in part numbers between the GT mufflers for a manual (p/n FI-7849-L or -R) and the one for automatic (p/n FI-7991-I-L or-R). My question is: what is the actual difference between the two? Anyone cut them apart to find out?

Which is the preferred and why?

Animal's 3rd · 07-17-2008

There really shouldn't be any difference at all. They should be the same muffler. I wouldn't be able to explain to you why Ford labels them different.