changing speed density to mass air on my Bronco, will it make any difference on performance?

 

Yes it should make a big difference! Of course if you upgrade one unit you will have to upgrade another to feel a worthy difference so you may want to upgrade to a bigger BBK throttle body and use a granatelli mass airflow unit, also may want to get some higher flowing 32 lb. accel injectors and a pair of BBK 1 5/8 primary tube shortie headers and then to make it all work properly together you will need a hot computer chip and a cooler thermostat Just my opinion from prior experience on my 89 5.0, good luck and enjoy!

 

In stock form, not much, but if you spend the time and money on all the things KDS mentioned in his post then, yeah, you will see a difference. The biggest advantage to swapping to mass-air is the fact that mass-air can compensate for a much greater change in cam setup than speed-density can even hope to acheive. This adaptability makes performance mods in the cam and valvetrain department much simpler and easily "accepted" by the EEC system.

 

the question came casue i've already change my throttle body, intake manifold, headers, cam, a computer chip, and electric fan, plus little here and there things...thanks...