Cheaper?

 

If they can sell a 25" glasspack for 29.99 then why wouldn't a 12" be cheaper?

 

I finally had it ran back to the factory location and kept it straight piped. It is quieter than it was but I think it is more annoying than before. Before it was loud but sounded like an old tractor, now it is slightly quieter but is borderline fart can, and I HATE fart cans, and 4 cylinders in general, unless it's a 4bt Cummins.

 

I had a glass packed on mine but it sounded too smooth for me, so I ran 3" pip from the manifold back to the axle and put a turndown on it. Ol gal rumbles now!

 

On a 4.0L, you won't notice any difference in power between the two. A glass pack will flow better, but a single chamber still flows well. Go with the one that sounds best to you.