Currently have a stock L69 305 with the magnaflow hiflo cat and cat back system with 3.5" pipes out back. Some have told me that this may decrease my torque which to me is counterproductive with this configuration.

I certainly do not want to give up low end torque
Any input on this?

 

Nobody knows?

Would freeing up too much exhaust be more detrimental to power/torque output?

 

Well yes if you were to say run open headers you would lose.

But the 2055s should open up enough to give the engine some breathing room as long as you have a decent system going out of it. Lets say you bought a catback already made for it, they are designed to give you the most power/torque.

Stock manifolds are very restricting.