Ive read a couple times that people with a lq9 need to drill another hole in the block for the procharger bracket. Is this true? Where will i need to drill? Any pictures will help greatly. I know the alternator uses one less bolt then a ls1 does. Is that where I would drill?

 

yes, but you only wanna drill as far as 1/2 inch in to the block matierial. i did this for a buddy and it was a pain in the ***.
best way i could suggest to do it is to install the bracket minus the blower, snug up all existing bolts that have holes and then us a center punch to ensure you get a good center. you should wrap the punch with electrical tape to ensure your best centering, or like i did, i used a large aligning punch and ground it down to a punch tip, this way it fit pretty straight in the hole, i did this on the stand, if your doing this with the motor in the car, be careful and make sure to use a right angle drill, put electrical tape at the 1/2 inch point on the bit so as not to drill too deep and ensure to use a good tap kit with matched bits. GL!