Hi.

I am getting a lot of different answers on ths question.

First let me say this is about my daily driver Chevy Caprice. It has the 305 engine with 4 barrel carb.

Just got new muffler and tailpipe, a few days later noticed the tailpipe was smaller than the one I had before. Measured it. It is 2 inches outer diameter. The old one was at least 2 1/4 inches.

Called up a different exhaust shop and they said 2 1/4 is the standard nowadays, but the 2 inch was the norm before they added the resonator. He said they put on 2 inch sometimes today, since they are cheaper, and that I should not notice the difference in performance from the 2 1/4 inch.


I THINK the car is a bit slower now, but it was having a problem before I got the new exhaust anyway. It is slow between 30 and 50 mph, accelerating. Seems to take longer to get to 50. It doesn't cough or die on me, I can give it gas but it doesn't go much faster as I press down the pedal unless I almost kick in the 4 barrels. It cruises just fine up around 60 to 80, just a little pedal keeps it sailing along.

The inlet and outlet at the new muffler are both 2 inch. They expanded the inlet to fit the intermediate pipe.

I have seen a couple other Caprices out there with the 2 inch pipe but most of them have the 2 1/4.

The Y pipe where it goes into the cat is only 2 1/4 inch OD.

What about it? Is a 2 inch OD tailpipe really normal for a 305 carb V8 ? What would be the symptoms of exhaust restriction ?


Thanks

 

you should be fine with a 2 inch, but if you are concerned with performance throw everything away and get a full 3 inch mandrel bent system.