Why does my 96 Chevy 1500 die when i come to a stop?

We replaced fuel filter, distributor cap, fuel pump, u-joints and barrings in drive shaft.
Before this problem started we were having another issue with it starting when ever it
wanted to. Sometimes it would sometimes it wouldn't. When it started up the last time
we took it to get it fixed and drove it about 35 miles at 70+ MPH and when I got to
town and had to slow down it started jerking and tugging and wanting to cut out at 40. I
kept it going  at stop lights in nuetral and it completely quit about 100 ft from the shop.
All the above mentioned was replaced and now it just cuts off at a complete stop.