Greaseless weights

I am looking into adding greaseless weights or sliding weights to add to my stock sheave as someone said that will be pretty close to the same top end as adding a machined sheave...Do any 450 owners have any experience with these weights? I was going to get a machined sheave BUT, they just raised the price on UTVCRAP to $199.00, $25.00 more than yesterday!!!!! More than the 660 or 700 sheave...They said the reason was is Yamaha is charging them more...Really? They said they will give me a $50.00 core if I send the other back in in usable condition...Can someone recommend a place that is cheaper?

I went with a machined sheave they didn't offer the OverDrive weights when I got mine so I am of no help with that one. I don't know about the UTVCrap sheave I have never run it but the sheave I got from 2X with the whiterhino450 cut is well worth 200$.. The sheave alone got me from 36mph to 40mph.. I know 4mph ain't a lot but it really does make a difference.. I also recommend 12gram weights for the 450(stock is 14g) they help let it rev.