2 1/4" or 2 1/2" Dual Exhaust?

[big_al_71]

I am also running 2 1/2 with a built "406"

[cwilkie]

My truck is actually a 396 bored .060 so I think that makes it a 408. So I think I am going to go with 2.5" dual exhaust with glass packs. What do you think?

[jbristo67]

Originally Posted by cwilkie

My truck is actually a 396 bored .060 so I think that makes it a 408. So I think I am going to go with 2.5" dual exhaust with glass packs. What do you think?

I think they are too loud. lol Does that make me old

[americanmusc1e]

Originally Posted by cwilkie

My truck is actually a 396 bored .060 so I think that makes it a 408. So I think I am going to go with 2.5" dual exhaust with glass packs. What do you think?

if you have a modified engine that revves to a higher rpm than stock, use the 2.5 pipes
If you have a stock or near stock engine, use the 2.25 pipes

[Green Machine]

My vote is for 2.5 duals also. 2.25 might be a little quieter, all else being equal, but 2.25 dual are really for a smaller small block like 283-305. I don't think engines are designed to run with back pressure, they are tuned to run with the back pressure they have. Change the backpressure, change the tuning to run right.