Everything you do that isn't a slip-on exhaust will probably need some tuning to get it right.

Even a slip-on technically will need more fuel but you can get away without touching the carbs. Your bike will run slightly lean and probably have a miss at lower RPM though.

You /can/ gut the stock cans and put perf core and packing in them.... but instead of spending $40 per side on a decent re-pack kit and tearing two perfectly good mufflers apart, just ride it.

The money you save on the perf core kits will probably get you a decent used slip-on anyway. I find them all the time for less than $150. And it doesn't make too much of a difference what bike it comes from if you have any idea about making brackets, hangers, etc.

Slip on pipe in most cases is a fancy word for "cool looking glass-pack".

In fact, you could replace your muffler with a $25 glasspack from McParts and negate the whole situation if you don't mind the look.

If you just gut the stock pipes and leave them hollow, you get zero sound attenuation. Know what that means? Obnoxiously loud, and not "throaty" at all... in fact, it'll probably sound like a cacophony of dying cats in heat on 'fish night' behind the local Italian restaurant. With a mix of asthma and whooping cough leading the orchestra.

Thanks for the advice. I am going to go to my local cycle junk yard and see what I can find. I think I seen a Cbr and a gsxr there, I'll yank the muffler off one of those if they are aftermarket brand and not stocks. I have a 4 into one exhaust so only need one. In handy with making things so I can fabricate hangers and such.

Search for "poor mans exhaust" tells you how to do it without the welding. I did it to my 2000, 600 and I love the sound. Havent noticed any difference in fuel consumption or performance.