can i overclock my cpu using tape

Solution
Doubtful. The Dell system in that video has 0 ability to OC, there's no physical multiplier to change by jumper pins, or bios multiplier able to be user set. The electrical tape just bypasses certain bios restrictions and sets the cpu multiplier higher. With your board, OC is an option, so the bios won't include bypasses as it's already open. You could always try it, but Dell OEM bios is custom written for Dell, so is somewhat different to aftermarket bios setups.
Doubtful. The Dell system in that video has 0 ability to OC, there's no physical multiplier to change by jumper pins, or bios multiplier able to be user set. The electrical tape just bypasses certain bios restrictions and sets the cpu multiplier higher. With your board, OC is an option, so the bios won't include bypasses as it's already open. You could always try it, but Dell OEM bios is custom written for Dell, so is somewhat different to aftermarket bios setups.
 
Solution
Not for that CPU. The tape mod is real but it dates back to the Core2 Q6600. It allows then to run at 3GHz but performance might not equal the Q9400 you already have.
Here is one running an X5470 Xeon at userbenchmark.com.
https://www.userbenchmark.com/UserRun/9028241
The G41 chipset supports that swap. delidded.com has the instructions for that conversion.
https://www.delidded.com/lga-771-to-775-adapter/
That will get you 3.33GHz w/o any overclocking.