Looking for the name of this part...

I'm looking for the name of the part that I've seen on people's engine's....

It's the bar that stradles across the top of the engine block/intake, what's the name of this part and what's it's purpose, because I was wondering if I needed to add this to my 90 mustang gt.

I'm new so please forgive my ignorance I'm still learning

Thanks,
Rat

Yea I believe that's the one, what's the purpose of this ? Is this something I should invest in ?