Youtube "1uz 10,000 rpm" & "ITB 1uz" both sound amazing. Whats done to the engine? What size exhaust & routing scheme?
Generally an I.D. thats too large for the engine output causes the raspiness. You want exhaust pulses to exit with as much velocity as possible but at the same time reduce back pressure. Larger the size, lower the velocity. A well bent 2.25" "X" "Y" or "H" pipe w/ 1 turbo style muffler/side will have a nice "clean" rumble.
Also, a well engineered set of headers really allow the 1uz to sing. (rushimports.com.au) (S&Sheaders.com)