exhaust/intake

Has anyone experienced increased hp/mpg with an exhaust and/or intake?

I have an 88 d 50 2.6.

I'd rather hear from someone who has actually experienced it than theories and claims.

Thanks

With the addition of a Starion turbo 2.6L in my MM, I have gangs more power than the carby NA 2.6L. There are discussions of replacing the Mikuni carb with a Weber on other Boards. Second, there is FI in Oz available. Exhaust headers are made by Pace Setter and Thorley but are not smog legal, at least in Cali.

if u put a bigger muffler on an maybe an after market air filter. remove the fan an put an electric 1 . anything u do to take drag off the motor an help the free flow of air from the begiining of the air filter to the exhaust tip will help with power an increase mpg