For those of you still running manifolds. The car I'm buying(1991 RS 305TBI) has the stock manifolds, high-flow cat, and no muffler. It's the single 2.5" pipe back over the axle, then into a 'Y' and the dual tail-pipes. It's not loud at all...Gives it a nice rumble to it, and doesn't get really loud when you get on it hard.

By the way, I'm brand new here. I currently have a 1969 Camaro Z/28 that I'm restoring. It has the DZ302, M21 gearbox, and the D80 spoiler package...

Edit:
I'd also recommend you visit anti-****.com/phpBB2 and say hi...A bunch of people into making fast cars, and against ricers...(anti-idiot, not anti-import)

A muffler will sound better.

Cool 1st Gen.

Some mufflers would sound nice... I don't like flowmasters on TBI or TPI engines. The idle is too smooth to sound right. A carb'd car with a lumpy cam and some flowmasters would sound pretty cool...

What kind of mufflers would you recommend on a fairly built 305 TPI with a cam, headers and full dual exhaust without cats as far as exhaust goes. I want to put in an H-pipe and it also needs new mufflers because they rusted and died. I can't have a dual inlet/outlet muffler because of exhaust placement so I need two separate, less expensive mufflers. I am looking to have a mix between a tuned and muscular sound, not real rough but not too quiet. If you guys have any suggestions other than flowmaster or glass packs I would really appreciate it. Thanks.

Adam

what about the chambered mufflers from summit??

The thing about mufflers is that it's all opinion really if you're going for sound and not CFM numbers.

Personally I like Hooker catbacks, and despise Flowmaster (every ***** in town has a 80 series, so I've grown to hate it, even on muscle cars ).

Something you should think about... you need atleast a 3" exhaust, mandrel bent in order to flow free. 2 1/2 isnt really enough. And if you dont have headers then you shouldnt expect a gain from the catback. And vice-versa, if you have headers and still 2 1/2" exhaust you'll still be choking it.

A short list of exhausts that I can think of off the top of my head that you can search for:

Hooker
Flowmaster
Banks
SLP Loudmouth
Cherry Bombs
Glass Packs
Edelbrock
Spintech

There's always someone who likes one of them, it's all just your own personal opinion

Have fun, and keep your foot into the happy pedal fellahs

2 1/2" full duals isnt enough? Heres what's done to my motor..roughly (this was my uncle's car before me and he did all of the engine work, Im not sure as far as brands of mods).

-1 5/8" headers
-full dual catback (it already has 2 1/2" piping but my plan was to redo it)
-No catalytic converters
-High lift cam
-1.6 aluminum roller rockers
-chromoly pushrods
-new pistons (again not sure on brand yet)
-45,000 volt ignition
-new distributor
-8.5 guage spark plug wires
-ported throttle body
-cold air intake
-New alternator (not sure on amps)
-Moroso valve covers
-New fuel injectors (not sure on rating)

There are a few more things but I cant think of them, what do you think would perform best with this engine? I know Im going to do the full duals with the H-pipe but is 3" the right number, it seems like that would be killing the backpressure too much? The reason I ask is my uncle is the one who suggested the 2 1/2" duals all the way back and he is the one who built the motor.

No such thing as a dual catback. Is dual exhaust or does it a catback?

My bad, I read catback, which is a single pipe.

Your uncle is right that 2 1/2 inch duals with H or X pipe (IIRC X pipe is proven better) would be good for your setup.

What you probably have is a catback setup that goes from 3 inch from the cat, to the muffler where it splits out to dual outlets. This shouldnt be confused with duals because it just simply isnt

Now, for your backpressure thing.

Backpressure = bad in any occassion.

What people dont understand right away is what backpressure gets confused with Delta Pulses often times.

Delta Pulses, which is just the little puffs of air when the exhaust gasses come into the headers/manifolds will pull more air out of the chambers of other cylinders (which is called scavenging, and is why headers give you more power, plus free-er flowing)

If there's gaps in the delta pulses then it will reduce Volumetric Efficiency (aka VE). In a free flowing exhaust you should see 100% VE. Though this is not common... at all. But it's more what you're aiming for, and if the delta pulses dont match up, then your VE will drop as well.

This is why an X or H pipe is needed with a true dual setup. Without them then the there will only be one bank of cylinders delta pulses, which will give you bad VE.

As a rule of thumb, you should put the H or X pipe as close to the headers as you can, for this reason. So the sooner the delta pulses can get together, the better your VE will be.

Ljnowell, or anyone else, feel free to correct any of this. I'm sure I missed something, or said it in a misleading/incorrect way somewhere.

Sorry I didnt mean dual catback, right now it has duals all the way back without a crossover. I want to redo the pipes anyways and make the routing a little cleaner and add the crossover with a different muffler.