gt fast

for the rc10gt with .15 motor. im trying to add a bunch of items to my truck this week. now so far i got rpm front and rear a arms, rpm rear bulkhead, and rpm ball cups. my clutch is bad so i guess im going the route of the M.I.P 4-1 clutch, is it a good choice? im also looking into rather switching from dogbones to cvd;s is worth it or not. as well as how much better is the robinson steel diff gear then the stock one. and dopes anyone know a good ratio to run, im pretty sure im still 66tooth spur and 15tooth bell, id like to get a setup for more top end. also does anyone know what the pipe that comes on the rtr rc10gt is, is it the associated torque pipe?. thanks i need all opinions on the parts i mentioned as well as any others you can think of. im trying to get more power and top end out of this little guy. thanks