Hey, I was looking at buying a Series 44 Flowmaster Muffler but they want to know my In/Out size...whats the easiest way to check that?

Thanks
John

 

Since we don't know what you're driving, I'll guess it's a Blazer with a 4.3L. If so, you're inlet might be 2.5" and the outlet 2.25", but the inlet might be 2.25" and the outlet 2.25, like mine. A pair of calipers would be the best way to measure.

 

Oh, sorry, I forgot to mention that x_x...its a 92 K5 with a 350 v8.

 

Well, in that case...I don't know.
That's why it's a good idea to put your vehicle info in your signature.

 

I believe that stock is 2-3/4 IN & OUT. You may want to measure yours just to be sure. I would highly doubt that it is the original exhaust on it now.

As far as the easiest way to check it, well... You could take a flexible measuring tape and wrap it around the outside of the pipe. Take your measurement and divide it by PI (3.14159...). Or You could open up a pipe wrench until it slipped over the pipe and then measure the distance. It'll give you a close enough idea of what it is.