Will a SI/SO 6" round Magnaflow muffler work on my 4.2L V6? The book I'm looking in has round mufflers and turbo type mufflers that are 14" long. Both from Magnaflow. I was thinking the round kind would work a little better. Any thoughts on this?

 

6" round would work just as any other. 6" round just is a smaller canister volume and would be louder than a 5x11" oval of the same design. Stay away from the XL turbo style, unless you realyl want to have that Flowmaster sound. Not that Magnaflow woould sound like Flowmaster, but if the only reason to choose a turbo design is because you really like Flowmaster. The design is poor for performance. Stick to the straight through design.

 

OK. Cool APT. That's what I was looking for. Thanks.