Belt Length for 351w with U/D pulleys, A/C, P/S
 

On my 351w block with A/C, power steering and underdrive pulleys (bypassed smog pump), an 86" belt fit perfectly within range.

Note: The accessory configurations are as on an 87-93 Mustang.


(As with any belt size recommendation, the length can vary because of different size underdrive pulleys, but this should get you close.)

Which way was it routed?
Does the belt go down from the alternator straight to the crank-pulley? Or the other way: belt goes from the alternator down to the top of the water-pump pulley and nearly touches itself by the tensioner (not recommended). :shrug:

It's routed the correct way from alternator to crank (water pump wrap is opposite from stock).

:werd:
I've heard of belts shreding due to running the belt that way. I never run mine like that. :nono:

On a stock 5.0 pulley setup with smog delete it is 83-84" with the belt configuration Brian mentioned

93 cobras are shorter but I am unsure at this point the exact size. I bought an 83" belt and it was to long