better slipper clutches

[A RC Dude]

Hey, I need a better slipper for my rustler and my e-maxx!
My rustler in running a MM7700KV system with a 2s Trackpower LiPo and my stock clutch is as tite as it can go becouse if it even starts to slip it will heat up and start slipping more and more! and within about 5mins it's so hot the spur's starting to worp. The problem is that i love floring it all the time and with the clutch that tite, the diff gears blew not long ago and i'm just now getting the new one in. I'd like a slipper that will slip a little without getting weak or real hot! Any ideas?
And as for my e-maxx, I am getting all the 3.3 parts for the driveline and metel idle gears for the tranny so i can install a 8XL motor and MM ESC. It will only be running off of 12 3800mah NiMH cells and a UBEC for now but i hope to get another 2s trackpower as soon as i can so then it'll then be running off of 4 LiPo cells. and from what i heard, that will be too much for the stock clutch. What slipper would work best in the e-maxx with that setup?

please keep in mind that i really don't need to spend that much money sence i get roughly $10 a week to spend so it could take a wile!

I appreciate all the help!