I have a '98 with a 360. We swapped a 318 for the 360 this summer and had a new computer done. Has run great!!! Just got in to start it and as long as you have a little gas in the pedal its fine but stalls out immediately once you let off the gas. Where do I start? Thanks for the help!

 

Check into thePCV valve and the TPS (I'm leaning toward the PCV valve being the culprit)

 

you might also check the IAC and the TB, I had a similiar problem on my D, and on my old truck with the 360. Hope it helps

 

on my dads 96 dak it was a bad timing chain, they would go on that truck every 30-60k miles