loose slip on reducer!?!?

[sideways]

i have a fmf powercore 4, with the factory head pipe. there is a reducer to fit the slip on to the factory head pipe. this reducer fits tight on the slip on, but loose over the stock head pipe. im getting a lot of exhaust blow by from this point, thus losing power.
anyone else have this problem? i think the main culprit is that its made from aluminum, and wears down easily. any ideas on the fix? buy a new one, or is there something i can do to the one i have to make it tighter?
thanks for the help!

[mojavedude]

you can buy exhaust sealler at alot of car shops. its like tape or some times it comes in a tube and hardens. or theres this other stuff i saw thats made to repair holes. its kinda like a roll of plastic that you wrap the exhaust with then you put some wire mesh down to hold it, i dont know. i think exhaust sealler would work fine