Should I do a muffler or high flow cat?

I was also thinking about a 3" down-pipe, 2.5" high flow Magnaflow/Carsound cat, and stock resonator and stock muffler until I get rockers, PCM, and ported mani'*.
Does this sound like it will be ok, or should I do the muffler first.
I was thinking that I could do the DP and cat first and that way the air flows easier, but will still have back pressure without being too loud.

P.*. Anyone have the part # for the correct Magnaflow/ Carsound high flow cat for my car?

Yeah the down pipe and cat make a good combo. The stock res is just a straight through pipe so you should be fine. Change the mufflers after they burn out, stock is still good.

3" DP? You might have to do that so I know if I should do it .
If you have a muffler go and put that on, every little bit helps. But if you dont do the cat.

I would like to do the muffler, but before I do rockers, PCM, and ported mani'* I think the muffler would be to exhausting for the engine. I also want to keep it somewhat quiet -after all it is a Bonneville, but it'* not gonna be so fast that it would need to be screaming loud.
I was going to call and cancel my appointment for the muffler install, but instead I'm gonna see if they can just put the DP on tomorrow instead, and the cat late next week.

P.*. How does your exhaust sound now with the Magnaflow?

You better make sure that the DownPipe you get will bolt up to your rear exaust manifold. I just recently installed a rear ported Grand Prix exaust manifold that didn't bolt up to my stock Downpipe. Just beware!!!

They make it with the car right there on the hoist so they can make sure every step of the process conforms to the car it is going on.

I say keep the stock muffler, you wanna keep it a sleeper

Just bought a 2.5" Magnaflow Carsound highflow cat on ebay for $55.57 including free shipping. Now I just need to pick up a o2 sim or a 100k resistor (where do I put the 100k resistor in?).
Since I have the cat ordered I think I'll just reschedule my appointment for late next week and have the cat and DP done at the same time. Hopefully the cat arrives by Wednesday.

i understand the sleeper mentality, but lemme tell ya, this motor sounds surprisingly good with a magnaflow. i don't currently have the bite to back up my bark, but it'* such a pretty bark! i'd say i've lost a little torque in the low end, but when i get up in the rpms this thing roars and pushes me back in the seat a little bit. you'll be happy with the results, i guarantee it. with my current mod list i can edge a v8 thunderbird, and i'm proud of that

Seth'* is great! I like it a lot (makes me want a resonator more then i already did, as well).