what belt do i use?

hey whats up. im taking off the power steering and the a/c on my 5.0 and i also have the smog pump off also. i was wondering if i can use an alternator bracket from an early mustang 289/302 on my car ? and also what size belt do i need or whats the part number of the belt? im only going to have the crank,alternator and water pump pulleys. please can one of you guys help. thanks
 
well if you have a stock alt bracket with the stock pullies on em, use a 45in belt and she'll treat ya right!! if you have underdrives (I just swapped mine on) and it seems that it still fits nice and snug, so I would go with the 45 with either imo, it has worked both times for me..