Exhaust recommendations

[ECU PIRATE]

Since I finally managed to get the headers I was looking for, now is the time to start planning my exhaust. I am going to do a custom one off and build it myself. Since the state of Va. is requiring me to run cats on my truck since it is post 73', I am going to be running dual 2.5" id/od spun cats and 2.5" id/od mufflers.

Still deciding on whether to use glass packs or pony up and get some Flowmasters. My question is this: What size pipe should I use? 2.25" , 2.5" or 3"? My headers (Hedman HTC # 68316) have 3" collectors with reducers. I am just looking for something that will slip fit so I can weld it up.

The Pirate

[Sabaka454]

Kinda need to know more about your engine and drivetrain setup before making any recommendations.

[Dalaigh]

If your running 2.5 cats and mufflers, I'd run 2.5 pipes, going with 3" pipe just to have it step down to 2.5 at the cats and mufflers isn't going to do you anything.

Look into thrush welded mufflers, they have the same design as flowmaster but are cheaper and I find they don't drone in the cab

[Malo83]

Stick with the 2.5 pipes

[ECU PIRATE]

Originally Posted by Sabaka454

Kinda need to know more about your engine and drivetrain setup before making any recommendations.

Rebuilt 350 With Edelbrock 3702 cam , stock quadrajet , Edelbrock 2101 Manifold, muncie m20 4 Spd tranny, 305 Heads
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[ECU PIRATE]

Originally Posted by Dalaigh

If your running 2.5 cats and mufflers, I'd run 2.5 pipes, going with 3" pipe just to have it step down to 2.5 at the cats and mufflers isn't going to do you anything.

Look into thrush welded mufflers, they have the same design as flowmaster but are cheaper and I find they don't drone in the cab

Thanks. I have been looking @ the Thrush welded mufflers due to the price (about $ 30.00 US) right now. Some good and bad things out there right now on these. Some good deals to be had on Flowmaster Series 40 & Super 44's right now though (about $ 60.00 US). Decisions, decisions....................

[THE "10" SILVERADO]

I agree with the 2.5" also.....I've been looking into new exhuast systems to...heard alot of good about the Thrush's but also I know I love the sound of Flowmaster 40's.....I have heard some about the 44's but have never heard them for myself so I can't really say anything about them

[2badgn]

I put a Gibson 2.5 inch into 3 inch exhaust on my 84 1 Ton GMC and I love it. Its stainless steel and was $700 but its going to last at least 10 -15 years. U pay what u get for- Sick and tired of spending $100 every 2 years on those cheap ass Walker tailpipes/mufflers.

[79beater]

How is the clearance with the Hedman HTC # 68316 headers?

[nbpro]

Header sizing and length is where your power is.

All you want the exhaust system to do is get the gases out with minumum backpressure
2.5 pipe is good for 450hp (in theory). mufflers will make a difference too. Use a mandral bent system with a straight through muffler design such as the Dyno Max Ultra flow. Mandral kits are no more money that a muffler shop kink job

Mandrel bent exhaust systems are the ultimate step in performance. Mandrel bent pipes don't lose any pipe diameter in bends, which means more flow and more overall performance. Having a full mandrel bent system also makes your vehicle's powerband more tuneable.

[85Bowtie]

That's basically a stock engine. Anything over 2.5" is going to be a waste. Header size and length isn't going to mean much either with that cam and heads, so any header that fits will just free up a little low end torque.