Replacing stock muffler with Flowmaster

Lou'sZ · November 19, 2003

I have a 98 Z71 with the 5.7 and 4L60E. The truck is stock and will probably stay that way(budget). My current exhaust is the stock two pipes in and one pipe out of the muffler, with separate cats on the inlet pipes. I'm considering replacing the stock muffler with a like Flowmaster, either the Big Block 70 or 50-SUV. I'm looking for some growl and slight performance improvment. Since the truck will remain stock, I don't want to invest a lot in a whole system. Also, the stock system still looks to be in great shape. Which of these two Flowmasters is the better choice?

DSZ71 · November 19, 2003

Since "growl" is what you want then go with the 70 series, the 50 series is less noisy. If you want good performance with a slight growl, I was gonna say try the Gibson system. I am very happy with mine!

Black03SS_NJ · November 20, 2003

I am pretty sure that the biggest dual inlet 70 series is only 2.25". So that is probably too small for your application. I would look at model 530504, which is for duals (which I am running), or the other 50 series that is dual 3" in, single 3.5" out (I forget the model #). That way you could keep your factory tailpipe and save some $. The only downside is that the 50s may be a little louder than you want.

You can find the dual in/single out on sale here:Flowmaster

Lou'sZ · November 21, 2003

Thanks for the ideas. I'll probably get the 70 Big Block or 50-SUV closest to my stock pipe size and take it to a muffler shop for installation. That way they can weld on reducer or enlarger adapters. My real question is will the 70 be to quiet and the 50 to loud? I don't want my wife to b**ch everytime she rides in my truck. LOL! I have no idea what these two mufflers sound like and I would like to get the right muffler on the first try. I do want "some" deep tone.

Black03SS_NJ · November 21, 2003

I have no idea what these two mufflers sound like...

Check out flowmaster's site...they have sound clips of all of their mufflers.

MIGHTY 4.8 · November 21, 2003

FORTY SERIES!!!!!! DELTA FLOW. RUN TWO.. SINGLE IN SINGLE OUT AND RUN THE DUALS

STRAIGHT OUT THE ASS END.I THOUGHT 40 SERIES WERE THE LOUDEST?? CLOSE TO THE ORIGINAL FLOWMASTERS BEFORE THEY HAD ALL THE "SERIES" MODELS AND THEY WERE JUST PAINTED WITH ORDINARY BLACK SPRAY PAINT.