how do they all relate? i've read in some places that switching exhaust can actually decrease torque by a bit

 

I believe that the way it works is that if you were to buy long tubes that are less restrictive you will lose torque but gain the ability to rev(hp), and if you buy a mid length or shorties you will get an even balance, but not a lot of both hp and torque. In my mind it is all in the catalytic converters because they rob you of the most power.

 

I thought LT's gave more lowend but you have to be careful of the diameter of the exhaust pipes. Do a search here on headers and you will find lots of info. Most people say that shorties don't make much difference with these motors. Mid-length may help some. I know messing with the exhaust WILL effect the lowend power. When I changed from the stock muffler to the Magnaflow I lost lowend power but if ran better above 3000rpm.

Do a search it will answer your question I think.

 

When you open exhaust you lose torque!!!

 

i lost low end with my single flowmaster. lol. i got it back and then some with the intake though.

 

LT's do give more lowend but you have to make sure that the "full length header system" is tune for this. The Dynatech system I have made a big diff in my truck. I then drive it down to S.A. and Allen tuned it for me. I could tell a big diff before and after the tune. The cats and the equal length headers are what makes all the diff in lowend. The size in the primaries is what gives you the flow to make the HP on the big end. I could be wrong or some people might think I'm wrong. This is what my head and engine builder said when I built my blown small block.