Hello, I have a Texas speed 408 coming, I will be using 317 head's and it is spec'd to be around 10.7-1 comp. ratio with those head's, TBSS intake, 90 mm DBC TB, TSP 228R 110 LSA cam, it will also have schoenfeld longtube conversion header's, the engine is going in my project truck, which is a bagged 95 chevy crew cab stepside. It's a big heavy truck and I want to keep all the low end torque and power that I can, I have read lot's of thread's about exhaust size but I am still unsure about whether to run 2.5 or 3 in pipes due to the size of the motor. I am planning on running dual's with an x pipe either way. I would like to hear you guy's opinion's on what size pipes you would run. Thank's

 

I run 3in duals only way I would do it on a 408

 

Ok, thank's, anyone else have an opinion?

 

3" duals or at least a 3.5" single

 

It will definitely be dual's, because of being bagged they run separately almost to the rear for ground clearance anyway, so I don't want to have to run them in to one single tailpipe.

 

3" duals. I had some cone sound reducers in my 3" duals and when pulled them out I picked up over 40hp on the Dyno..

 

Thank's guy's, this are exactly what I was needing to know.

 

i ran dule 3" to a dule 3" in/out maganaflow x pipe to turn downs.. love it..