needing exhaust advice

[ran83]

So i did a full custom exhaust my self to my factory 12a. I whent with a header based off of racing beats basic model, running into 2 3/4 pipe with a high flow cat into a off brand
N/a "turbo" muffler.... Heres the problem ..... It sounds terrible on top end. Below 4000 rpm it sounds like a veast but on the top end i have way too much rasp or rattle- ish sound. Kinda sounds like a cross between a lawn mower and a pissed off bumple bee in a tuna can.... Now before any one jumps in my ass i know that the muffler is gonna be the first thing brought up but do know people using similar set ups with same muffler on piston motors and they sound great.... But if it needs to go then so bee it but would i be better off doing away with the cat and doing a resignator or should i rethink everything and go a new rout.... Any suggestions. I have money and or tools benders welder and knowledge at my disposal...looking at like $350 to work with...