A 3000+ is a 1.8 GHz CPU with a 9x multiplier on a 200 MHz HTT bus.
A 3200+ is a 2.0 GHz CPU with a 10x multiplier on a 200 MHz HTT bus.
A 3500+ is a 2.2 GHz CPU with a 11x multiplier on a 200 MHz HTT bus.
If you o/c the 3000+ to 2.2 GHz (9x multiplier on a 244 MHz bus), it would be slightly faster than a 3500+ on its 200 MHz HTT bus.
If you o/c the 3000+ to 2.2 GHz (8x multiplier on a 275 MHz bus), it would be slightly faster than a 3500+ on its 200 MHz HTT bus & the above o/c 3000+ on its 9x multiplier times 244 HTT bus.
The key word here is "slightly". It depends somewhat on the application, memory settings, motherboard, etc.