what will give me hp gains with out costing me more than 300 dollars

 

What kinda mustang r u driving? a GT or??

 

a 3.8l v6

 

cold air and a pulley , exhaust usually costs around 300+ itself, but yeah you can also get a cai and throttle body if i`m not mistaking

 

get a used nitrous kit man.

 

what year? if its a 94-98 id look for a t-bird supercoupe set up for around that price, could be a little more,

otherwise, i would get a t-lok and a K&N drop in filter, t-lok wont add power but it will put power to both wheels

 

Thanks guys the idea's are great ill see what i can do