i was wondering if anyone grinded a set of 10-66's to 63.5 grams and how did u do it. Grind the sides. Thanks.

no dont grind the sides! gring on the inside close to notch.

I've heard three different ways to do it on the sides, underneath and drilling holes to lighten them up. If you look at polaris weights they seem to differ in width between weights 1066 vs. 1074. I've never done it myself but have done some reading on different forums and there are alot of different opinions on the subject.

If you do not want to change the shift curve, grind along the sides equally. If you are looking for more rpm in an area, then grind along the back side. This is what I have been told. I personally never grind weights. I go to a different weight, and/or profile to achieve what I want.

I have ground some weights to get what I want.

I have recently ground a set of Polaris 66gr to 65gr for match as well as have a set of 66gr ground to 64gr and matched.
In all cases I have ground material from the back side of the weight from the tips to the middle section.
In both cases I was looking to retain the initial belt squeeze and initial upshift of the heavier weight while lightening the tips to obtain or keep rpm.
Part of the reason was to get a 64gr weight that acted like a heavier weight on upshift but still revved out like a 64gr.
I was also being a cheap bastard as I had 2 sets of 66gr weights available.
Both weight sets achieved what I was after although no actual science to back it up.

I have always ground weights to gram match them and have always taken from the back of the tail and or mid section.

Was shown how to do it yrs ago by someone who has forgotten more about sled tuning than most know!