Belt Tensioner Question

[90GTFIVO]

I have underdrive pulleys with the smog and A/C deleted.

My question is, can I put the belt tensioner at it's normal position (pointing almost 6 o'clock)? I did not do the A/C and smog delete or the pulleys. The tensioner is currently pointing between 3 and 4 o'clock and isn't really doing anything. The belt is tight, even without the tensioner on it. I'm thinking the previous owner put too small of a belt on.

 

[Mustang5L5]

There is an arrow on the tensioner pointing to a small zone. This is the ideal adjustment range. If it's in this range, you are good. Outside of it, it's either tight or loose.