belt size for u/d

What I did was cut an old belt, install it, measure, then go to the parts store. You'll probably need 1" to 1/2" shorter to account for the tensioner.

Using all three UD pulleys will not change your belt length.

without the smog pump its a straight shot from the tensioner to the crank. it will be more than a 2" difference. your going to need a belt around 89-89.5". as mentioned above you might have to try a few different belts.

my belt is 88 7/8" but i swapped my alternator pulley to a smaller size. you will be able to return the belts you dont use so its just more convenient to buy a few at one time instead of having to make a couple trips back and fourth. the only way the stock belt will work is if you keep the pump or buy a delete pulley.

tstang21 said:

i might as well buy at least 3 belts. i want to remove the smog pump but 1 shop that works mustangs..no names...said that by removing the smog pump, the tensioner wont hold the belt long. only 6 months and then the belt gives away.

i have no idea

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the only way you're going to damage the belt is with misalligned pullies. other than that the the only thing to watch out for is the belt will strech slightly after it gets broken in a bit. if its not tight enough the tensioner will knock against the stop. there are two marks on the tensioner. as long as you are inbetween those two marks you are good. you might want to swap out the idler pulley. i got a new one from napa and it does not have the lip on it like the stock one. it makes it much easier to get a tight belt on there. you can also install an idler pulley on the tensioner to take up more of the slack if needed.