I would suggest going with 5 gram ... I do not think the 10 gram will work...I think the putter will still be too heavy but you can try it...on slower greens the heavier sole weights may be good but for general play I think you will prefer 5 gram weights...

IMHO, Chris

Supposedly that's why the newer Monterey added 10 grams more to the stock head weight, because the new pistolero grip was much heavier. This would keep the swing weight where he likes it.

Jamie,

I would try the putter with the new grip first and see how it feels to you.  Then you can add weight from there if you feel like you need to. 

 Chris S

Hi Jamie,

Do you have a preferred swing weight? Mark the center of gravity of the shaft, where the putter shaft balances horizontally level. Put on your favorite new gip. Then add or remove weight to the head until it balances on the same point as before. I did this when I went from my old second hand Circa 62  to my new 2012 California Monterey. I didn't have to really adjust my tempo and it was a smooth transition.

I'm not a certified fitter but this worked for me.

Hope that helps,

Michael