Correct Timing for 5.7 Vortec 1997

I installed a over built 97 vortec in my 96 truck. It was a small conversion, it already had the 5.7 vortec. But ever since the swap i have had bad gas milage. A couple of SES codes have poped up as well.
bank one and two system too rich
i turned the distributer a little , to match the old motor settings and it threw another code
Random cylinder misfire
it does this when in open loop alot, when i WOT it
i was going to check the timing but dont know what its suposed to be at, since the computer adjusts it.
thanks for the help

Does anyone know the timing, or where the distributor needs to be??
TTT

I'm assuming its still run by an OBD2 PCM. You will need a scan tool to set the timing. You need to have the cam retard(or camshaft offset) value read 0 degrees(+ or - 2 degrees) and you must have rpms over 1200 for value on scan tool to be accurate. A way to get it fairly close would be to get the motor to tdc on the compression stroke on cylinder 1, pull the cap off the distributor and line the rotor up with a number 8 in the distributor base, the 8 may be hard to see even with a light but its there

So put the motor at top dead center, pull the cap off the distributor and line up the thing that spins with the number eight wire????

Roadtrip, I sent you a private message with a picture of what you are looking for on the distributor.

I got the PM, and i already worked on the truck, no codes yet,, thanks brady