how do you do it with the dimes?
what does this do performance wise?

Nothing performance wise that I've noticed.

It should keep the hot coolant out of the TB in the summer. I haven't found any data that proves or disproves whether it was intended to keep the TB from icing in the winter or trying to keep temps down in the summer. Either way it can be blocked off.

You file down the ridges of a dime and get it to almost fit. Then take a socket of about the same size and whack the dime in by using the socket and hammer. You are done.

Does this have to be done when upgrading to the L32 lower and Gen V blower?

You don't technically have to upgrade the LIM for the Gen V. I cut the extra 3/4" off the L67 I had sitting around. You also don't technically need to do this for the Gen V blower because your adapter to throttle body plate will do it for you.

I chose to not have any coolant in my supercharger though. That way if I remove it for any type of work, there'* no need to drain any coolant.

so would you recomend this since I got the lim off or jsut leave it?

It'* your choice. If you don't want coolant in the TB, do it. If you plan on changing the TB..do it.

Otherwise..ithere isn't necessarily a reason to do it or not to do it.

I agree. I've been trying to determine the results for two years. I have temperature sensors all over the engines of both my cars now. It depends on the season and the weather.

Sometimes it helps, sometimes it hurts. Hot summer days will be the worst.

I suggest if you're not building a 'toy' or track car, leave it unplugged.