help with exhaust

[johnleewilson]

hi, im new to this board (well to message boards in general) but i have been reading on it for a while.. so, i own an 85 silverado 4x4 its get alot of new parts but its fair share of old ones too. anyways... The old exhaust setup was a Y-pipe, then the cat, then a 1-in 2-out muffler. The cat started coming apart and rattling around so i decided to look at new exhaust. I went to the local muffler shops and got some prices. I only found one that would remove the cat, and he was pretty spendy, so i went ahead and bought one of them 150 dollar dual exhaust kits out of LMC catalog. It had two glass pack mufflers and all the pipe needed. I also bought a set of 2 year old headers off of a friend for pretty cheap and put those on. the truck has all the egr crap on it but i dont have to do emissions where i live, so im removing all of that as soon as i put a new intake manifold and carb on it. the old exhaust sounded decent, it was real quiet and the cat rattled but it was ok. I took of the entire old system and then just put the new one on. I plugged up all the emissions lines as i was told too by some friends of mine, and then fired it up and it sounds like crap! at an idle it is nice and low but as soon as i rev it up it sounds like a big fart, real choppy like. it seems to run alot rougher too. i dont mind loud exhaust i just want it to run smooth. i checked and seems as though i have all the emissions lines plugged. any help would be appreciated. i am by no means a mechanic i just try and save money by doing work myself and screwing it up. err anyways thanks.