You need an 84.5" belt to bypass the smog pump.
Go to a good parts house like a NAPA dealer, not Auto Zone or simiilar places who don't know jack. Tell the counter guy what you need and he should be able to help you out.
Heres a link to explain more and shows you the belt routing.
http://www.fordmuscle.com/archives/2...ps/index.shtml