Dynomax vs Flowmaster?

I'm currently on the market for a new muffler, but I'm unsure if I should go with a Flowmaster alone, or a Dynomax muffler with new pipe? Any suggestions/recommendations? I plan to install a new cat at the same time, but havn't looked into any brands yet!

And does anyone know the size of the inlet & outlet pipe suitable for a '98 GC 4.0 (laredo)?

I think the inlet pipes are 2 1/4" (but not possitive) also i would recommend goign with the Flowmaster american Thunder system - on the flow master test it increased the horse power of a 98 KGC 5.9L by 26 HP.

Thanks dksob81, I've been leaning more towards Flowmaster anyways. I can't wait to install it in a few weeks to feel the difference!

I couldn't agree more.I put the American Thunder system on my 5.2 and I love it.It sounds great.It fit perfect and it helped my mileage.I got it from summit it was like $180 and it came in like 3 days

That's a really good sounding exhaust. I had a custom made prototype on my GC that was absolutely awesome, but the company never mass produced it for the JGC,, they made some adjustments to it and now sell it for the H2.

From what I hear industry wise, Flowmaster really stands behind their product as well, that's hard to come by these days.

Keep us posted!
~C

I had a Flowmaster 40 Series installed on my '98 GC today, along w/a new cat (nothing special) & so far I give it 2 thumbs up!

The sound of the 40 series is definitely more aggressive than the stock & it sets me apart from the rest, I havn't heard any GC's in my area sounding the way I sound now!

I havn't been above 40mph yet but I can't wait!