Leaf Spring Stiffeners

i was just wondering if anyone knows/has an idea about stiffening my rear leaf springs on a 2005 frontier. i phoned around and they don't make a helper spring for my truck yet and others want big money to add a leaf to each side. Any suggestions ??

Luca

Did you check JC Whitney? They often have items others don't.

thanks for the tip Paul, i will check them out...

Luca