I am leaning toward the magnaflow but heard a clip with corsa and almost fainted. Before I buy since it's not easy to hear the same car and setup for each system Which one would give me the most/best deep,low tone, growl at idle and good sound a cruising (80mph) and roar at WOT?
corsa exhaust, magnaflow, borla, slp.

budget is under $500 out the door chrome tips and all.
89 lo3 700r4 stock

right now I have rusted out split duals after the cat.

 

I guess I should have asked which is better on a stock v8 RS and what is the best combo (Y pipe and/or cat back) and how hard is it to exchange manifold for headers? I have big hands and will be working outside under jack stands.

 

There are some sticky threads near the top of the page that talk about the different headers and cat-back options. Out of the 4 brands you listed though, I'd go with the Magnaflow. The Borla and Corsa would be over your $500 budget, unless you got a nice deal used somewhere. As for the headers, in most cases it's as easy as removing the old and installing the new, as long as the bolts are game anyways, lol.