408 stroker motor/ exhaust?

[92_D250]

Hey yall, so getting towards the end of my project and don't know exactly how I want to finish up the exhaust. Hoping someone can help me get the sound I'm looking for.

I have a 92 W250 4x4 manual. Bought it with the 318 magnum in it. Ran great just a little sluggish so I got a 360 block stroked it out to a 408 ci stroker motor, built it mainly for torque, and i went back to a carburetor. Scat forged crank and bottom end kit, mild to mid on the cam, edelbrock heads, edelbrock intake, edelbrock av2 800 cfm carburetor, msd ignition with a stage 2 clutch, long tube headers, 3 inch exit....Dina said around 450 hp and around 540 ft lbs of torque at 3200 rpms...

So, I really have no experience with exhaust, I've read a few people say I should run 3 in duels like I originally planned, i was going to delete the cats entirely, some say i shouldn't, then others say I should only run 2 and a halfs, some say resonator, some muffler some no muffler but almost everyone I've read about was either my motor in an older mopar car, or a newer dodge truck... so I'm hoping I can get some help for my 1st gen situation.... I want it somewhere between loud and aggressive and throaty but maybe not completely unbearable on the highway lol, please help.

 

[Rob2gen]

For a high-torque 408 stroker engine in a 1992 Dodge Ram 4x4, the optimal exhaust system will feature long-tube headers and a true dual exhaust system with 3-inch diameter mandrel-bent piping and an X-pipe.

Here are your considerations:

• Long-Tube Headers (you already took care of this): These are recommended over shorty headers or stock manifolds because they provide superior flow and are better for maximizing low-end torque and overall performance in a high-performance, built engine.
• True Dual Exhaust: A true dual exhaust system provides better flow than a single system, which is necessary for an engine producing high horsepower (likely over 400 HP).
• X-Pipe or H-Pipe Crossover: Incorporating a crossover pipe (preferably an X-pipe) is crucial for balancing exhaust pulses between the two banks of cylinders, which improves torque and creates a better sound.
• 3-inch Diameter Piping: Based on a general rule of thumb of 1 inch of total exhaust pipe diameter for every 100 horsepower, a 400-500 HP engine would need a total of 4-5 inches of diameter. A true dual 3-inch system (totaling 6 inches of diameter) offers excellent flow potential without being too large to harm low-end torque, making it a good choice for a high-torque build. It also allows for future power upgrades without needing a complete exhaust replacement.
• Mufflers: Choose high-flow, performance-oriented mufflers, providing a deep, aggressive sound without creating excessive back pressure.
  
  
• Mandrel Bends: Ensure the entire system is made with mandrel bends. Traditional crush-bent pipes used at many muffler shops can reduce the actual pipe diameter at the bends, creating bottlenecks that restrict flow.

You could go down to your local muffler shop and they would tell you the same thing and make the same recommendations.

 

[92_D250]

Hey, thank you very much on reply and thorough explanation, it is much appreciated...should be getting her back any day now and I'm super excited about it. I'll let you know how it goes.

 

[Rob2gen]

That's awesome I was on track to build a 408 for my 2001 Ram 1500 from a donor engine I bought about 5 years ago. Ran into problems with the donor engine (had a hairline crack in the block) and the project was shelved. Ended up buying a new truck this year but still have the 2001 as I just can't part with it.

Congrats on the 408, especially going with the torque build and manual tranny combo!

 

[Rob2gen]

Oh BTW, I run a 3" flowmaster single on my 2001 and pull right at 300hp at the flywheel with matching high flow cat (using scan gauge). Runs better with the cat on... but quieter. I still have the stock exhaust manifold.