do a search for amp bypass...... this is a well covered issue, but since you cut off the terminal, you'll prolly have to run new speaker wire if you didn't leave enough to hook it back on..
second of all walmart sells the correct adapter kit, its the one that doesn't have the plastic spacers for chryslers and other models, which for most radios you don't need anyway.
I'm pretty sure theres a leftover wire that has to be hooked to the aftermarket radios blue remote wire, which turns on the factory amp which will make it work without bypassing the amp. or you can order the bypass kit from crutchfield, or find a local shop that has it.
I just went through this with my '94 xlt, and I just reran the wires fresh so I could put an amp under the back seat to push my 4 alpine 5x7s. pretty much figure if you utilize the amp, you'll have crappy sound and if you don't use it you'll blow the stock speakers if you listen to it loud, I think it says somewhere on here its like a 10watt system so your 40x4 or 50x4 Head unit will prolly give them a good workout and a short life (keeping in mind they are 13 year old paper cones).
good luck with it.
