This is a rough estimate for the 406 i have recently built for my 85 Z, how much more hp could i realistically expect with a full 3 inch exhaust and a good pair of shortys?

 

To be honest I don't think your going to gain much with a upgrade on the exhaust.My two cents is the bottle neck is before that in the heads/cam combo being mismatched to the 406 size.Is is why it is falling on it's face at 5 grand and has such a short torque curve.

 

I didn't say and should have that the intake runner for a 406 should be a minimum of 195cc to 200cc leaning more towards the 200 size.

 

With shortys a 2.5 system should be enough

 

Im pleased with it for what it is, it will never see 5k rpm and all the torque is right where I need it, I may upgrade to vortec heads at some point but I really have an ls based swap in mind when I'm sick of the 406

 

Good stuff!!!. You built a torque'er street 406.Nice.

 

Hope you have a good tire supplier..