Has anyone replaced the stock exhaust system on their regular cab 6.6' bed with a 4.6?

I measured my exhuast pipe just in front of the muffler and it is 2.5 inches.

Magnaflow said that their exhaust will work on my truck but it's 3", how would that fit?

 

The Magnaflow on my '97 had a 2 1/2" inlet and twin 3.0'' outlets. Also, an adapter (2.5 to 3.0) may be used aft of the cat converter.

 

I have a Magnaflow that was welded on my SCrew 5.4. Has a nice mellow tone. Not loud, but noticeable when it needs to be.