Question for my 2002 truck?

[UNTSS/T]

I just bought a 2002 Sport regular cab pickup. The truck has the infinity speeker/tweeters. I wanted to put in my old system which included custom made box w/ two 10"s, two 6x9 3-ways, and a 440 punch amp/4-channel. I was going to put in a new deck(JVC kameleon) but then I lose my steering wheel mounted stereo contols. So I decided to keep the stock deck. My question is, is there anyway I can hook up my 6x9's through the amp to the stock deck? A friend said I could not? I don't know too much about audio, can someone help??
Thanks.
PS The only thing I have done is installed the amp and the subs, any suggestions on what I can do to improve the sound??

[Tufiremn]

Run down to your local Circuit City, and tell them what your looking to do. You should be able to get a box the converts the line level output from your head uint to RCA. Then you can run the RCA cables to your amp. Won't sound quite as good as a full deck with preouts, but it will work.