03 5.3 exhaust

[wiseguy]

hello,newbe here on this forum,I have been asking around and cannot get a direct answer on the following..ok here goes..
I have a 03 excab stepside chev z71,5.3 engine,I want to add my complete left over exhaust from my 03 silverado SS,it will fit perfectly with the hangers,i just would need to take it to an exhaust shop and have them adapt the inlet because the factory SS exhaust is dual inlets..
my question here is will I gain as much as a magna flow or flowmaster cat back system?
thanks for any help..
terry

[03Sierraslt]

I would say that the gains would be very similar. I know that my stock exhaust on my denali was very free flowing and from what I can tell the ss and the sierra denali have the exact same exhaust setup. I personally would have to say that gains vs. magnaflow would be about the same, gains vs. Flowmaster ( I think the stock would be better then flowmaster) However flowmasters sound good( exept for resonating in the cab) I love the sound of my magnaflow, Its not quite as loud as i want but it sounds great.