Precision 7740 thermal pads' size.

Hello.

I am currently looking forward to replace thermal pads in my Precision 7740 as VRAM temperatures has been slowly going up over last 4 months.
But I after looking in every dell's manual there is no mention of them at all not counting their height.
I have already messaged support, but because my warranty ran out they wont' answer any of my questions.

Thanks in advice!