The top cover was square on the 99-00 and rounded on the 01-up

Coil packs had nothing to do with year. I have seen 3 different versions on all years.

How ever valve covers did change do to the PCV system routing.

 

Not sure on the head lights??? if you push the dome light button in and out 3x its supposed to bypass and work of the switch.

 

oh really? they mixed coils. reckon i just got a good pick with the 5.3 i bought

that's the 00-02. 99 has no override - i had to take my dash apart to disable mine

 

Some had round coils and I believe there were 2 different version of the squared coils.

what did you have modify for the lights???

 

my brother has a 99 and i have a 00. He cant override his lights but i can.

 

you have to get to the photoresistor (that little black bulb by the windshield), and unplug it. then you take a radio shack resistor (i forget what value - there're a few writeups around here) and stick it into the harness connector. tape it up & put everything back together. what it does is tell the BCM that it's always bright daylight outside, so it keeps your DRLs on until you manually use your light switch.

 

Intresting.... I wonder if you Update the BCM to 2000 specs if the lights would work like the 2000's