Thread: Exhaust pipe size question. 357ci SBC

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hey Guys,

Let me run this by you, with a little back story too.

This is my 2004 Silverado:



This is the motor in my 2004 Silverado:





.040" over, one piece rear, roller cam 350ci.
10.7:1 static compression
Patriot 'Vortec' heads, 185cc Int runners, 2.02"/1.6" valves
Comp XR276HR-10 cam, .504"/.510", 224/230, 110-106
Super Victor copy intake, Mighty Demon 825cfm
Hooker long tubes, 1 5/8"s primaries, 2.5" collector

Recently, I hurt the trucks original 4L60E. A PerformaBuilt Pro Race level 2 4l60E is on order, as well as a new Road Runner 9" 2800rpm stall converter.





While everything was torn apart, I decided to do something about the fuel system and get rid of the stock fuel tank.





Now, with the fuel tank & original fuel lines out of the way I can redo my exhaust too.

Previously, it was a dual 3" system, H-pipe, Flowmastr Super 40's dumped under the bed. But the drivers side bank needed to crossover and run parallel with the passenger side exhaust.

This time I'm going for more a traditional dual exhaust going down each side, with a H-pipe, still using the FM S40's. But now I intend to run the exhaust tips through each side of the bed.

Like this:



My question is this. Should I run 2.5" pipe to the mufflers to match the header collector size, than run 3" tail pipes. Or just run 3" pipe from the headers back, despite the 2.5" collector.

I'm thinking that if I can get a straight shot from the headers to the mufflers I should try the 2.5" pipe, as long as there are no kink bends. What do you guys think?

Cheers ~Mykk

its already choked i'd keep the 3" exhaust and get matching headers