Question about timing

Could somebody please tell me the correct way to set the timing on a 97 5.7 Chevy truck? According to my Haynes manual it says their should be a timing plate next to the vibration damper. Theres not one, it looks more like a timing sensor. I tried pulling plug number 1 and thought it was at TDC on the compression stroke and setting the distributor at plug one but it didn't work right. Any suggestions would be appreciated. Thanks DennisC

The timing is not adjustable and you do not use a timing light.The distribitor has to be set with a scan tool,+ or -,0 degrees.

Thats what I was told by a friend before working on this truck and I didn't mark the distributor when I took it out like I normally do. I changed the intake manifold and now it runs crappy and the service engine soon light is on. Sorta feels like the motor is out of time. I took it to AutoZone and they ran there test on it, and the codes says something like ignition misfire. I checked and all the connections are plugged in and followed all the wires to each plug from the distributor. So will the computer time the motor back up no matter where you put the distributor back in? I recently changed the intake on my truck and marked the distributor and had no problems at all. I guess because mines a GMC and my dads is a Chevy must be the difference........lol
Thanks for the help. Dennis