MMX has one for $450 and according to RacerX on YouTube you can easily install it yourself. I did a search for this subjects -surely it has come up multiple times - but couldn’t find a recent one. The $300 version is only ported and NOT polished. Figured if I was going to the trouble of installing, might as well get the better version. Thoughts or experience on these? I’m not going to say what their info says on HP gains as I know everyone has their opinion on the validity of those type of claims. Thanks!