Just did this very thing a few months ago. Engine runs like it never has - much more power and easier starting.
As Jim said, you may still have air in the lines. I know I've had mine idling after changing fuel filters, then headed up the street and it would die - still air in the lines. If you had it idling right, then it sounds like the timing is good. It won't change by itself to keep the engine from restarting unless you left the IP bolts loose.
Also, how are your glow plugs? Getting power to the plugs? Maybe you knocked a wire loose.
Mark Chapman DP member #653;
1983 K2500 6.2 Suburban, 4" lift, 35" tires, ATS turbo, Banks exhaust/intake, pyrometer, tachometer;
1986 K5 6.2 Blazer, 2" lift, 33" tires, Banks intake, pyrometer, tachometer
1963 wife, one owner, average mileage for the age but in excellent shape, a keeper
1992 daughter, low mileage, pretty, limited edition, but requires some money to maintain
1995 son, sports model, very fast & peppy, time will tell on durability and maintenance costs
"Grease is good"