Stock exhaust size

[Sqeejo]

I am putting in a new muffler and can't seem to figure out which one to buy. I am leaning towards the Flowmaster 40 series but I don't know what size to buy. 2.25, 2.5, 3.... my measuring says 2.25 but i want to be sure before I buy. Anyone else know? I have an 1983 K5 with a 350. stock manifolds and exhoust system. Just putting in a new muffler.

 

[bp71k5]

If your measurement says 2.25, then I'd buy the 2.25 version.

 

[Sqeejo]

If your measurement says 2.25, then I'd buy the 2.25 version.

My problem is that I am not sure I am measuring right. I just wanted some input from others that have installed Replacements.

 

[bp71k5]

2.25 seems to be most common, but depending on how old your truck is, the exhaust is one of the first things to rust off and be replaced.

If you are DIY'ing it, cut the old muffler off and measure the inlet right on the face to make sure the measurement is right.