Rite guys what's a must in to help the engine breathe on a classic Impreza

Any advice would be great

 

clean air filter, vac hoses + regular service

 

Depends what you mean by "breath" if you want it to go faster then the only way to do that is with a custom re-map, if it's not already had one, but you're looking at the best part of 600/700 sheets to do that.

Also depends which model you're talking about.

It's cheaper to sort the brakes and handling, fit some quality tyres then learn how to drive it properly, no dis-respect intended.