Here is an interesting question:
A couple of months ago, I put a set of drilled and slotted rotors on my car (front and rear).
The way I installed them, the slots on top on the rotor are pointing towards the back.
In other words, the bottom of the slot (closest to the hub) passed throught the pad as the car is in forward motion.
Therefore, the slot runs across the pad in an outward direction.
(Does all that make sense?)
Now, I wonder, is this right?
I see pictures of cars with similar rotors installed the same way.
Then I see the installed the opposite way.
Which way is technically correct?
The way I have mine makes the most sense to me.
I may be wrong......

 

Are they curved vane rotors? If so, the key is getting the vane pointed the correct way, to get air-flow thru the rotor. The direction of the slots wouldn't matter to me, if the vanes are rotating the correct direction to properly cool.

 

No, they are not curved vain, meaning the coolong fins in between the rotor surfaces.
I looked over an article in GMHTP where they installed slotted rotors on a 3rd gen.
My slots are pointing the same direction.
Makes more sense for it to go inside out like I did it.

 

This will make it easier. I might not be right with this one but here is a picture at least. Just let me know from the picture how yours are.

My brother has a......HAD a 97 Grand Prix GT with the rotors facing as those in the bottom brake picture. They worked awesome and I have seen RACE CARS, LE MANS CARS with the brakes the same way as his.....but have also seen race cars and le mans cars with brakes going the other way....who knows maybe there is no TRUE DIFFERENCE except in how the heat is dissipated, but if thats the case I doubt anyone is running 180MPH+ then braking to 45mph....just dont lay on your brakes.....pump them....its actually how alot of people need to learn how to drive.....WIHTOUT ABS

ABS= A B**** System

Lol. I made that up.

 

I agree with Dewey. The vanes are what matter. If the rotor is listed as a single part number for both sides, then no, it obviously doesn't matter which side gets which rotor. Otherwise companies list rotors as left and right.

And as far as slots go, no, it doesn't matter. I have a set of Wilwood SRP rotors that have the "wrong" slots, as judging by the above picture. I have some Wilwood GT rotors that really have neither of the curved slot patters shown above.