Just wrapped up the install of the 30" LED light bar we got from M & R Automotive - http://www.mandronline.com/ - they are also vendors on www.GMT400.com the 88-98 GM truck forum.
The stock lights on these trucks are not very good and my cheap ebay ones aren't any better. This upgrade makes a GMT400 as bright or brighter than any modern car. The difference is literally day and night
I have my light bar wired to the high beams via a fused relay, if I ever don't want it I can just pull the fuse and the lights can turn on with no key in the truck if needed. Even though the 30" bar throws an enormous amount of light only draws about 15 amps max so you can run it a long time with the vehicle off.
I considered a lot of options for the mounting of the bar but in the end settled on one of the simpler options, your needs and tastes may lead to a different setup. The bar comes with L brackets for each side and hardware to mount to a flat surface. I ended up getting longer hardware and spacers with matching washers.
The spacers drop the bar down about a half inch and it fits very snug in the shell. A small bit of the chrome on the upper lip was trimmed in each corner to allow the L brackets through. I taped up everything while I was working to avoid scratching everything to hell. The metal fins on the back of the light needed to be trimmed in the middle to fit around the hood latch support. This isn't a big deal just be very careful about cutting into the cord while working. I held a flat piece of metal over the cord when working near it so it couldn't get damaged.
The finished result is quite visually striking and extremely effective. I no longer have to worry about outdriving my headlights at night.
Low Beams vs High Beams (4HI mod + bar)
Overall, I strongly suggest an upgrade to your lights if possible and have found that LED is quite a good option for doing so. Check out M & R for LEDs of all sizes.
The stock lights on these trucks are not very good and my cheap ebay ones aren't any better. This upgrade makes a GMT400 as bright or brighter than any modern car. The difference is literally day and night
I have my light bar wired to the high beams via a fused relay, if I ever don't want it I can just pull the fuse and the lights can turn on with no key in the truck if needed. Even though the 30" bar throws an enormous amount of light only draws about 15 amps max so you can run it a long time with the vehicle off.
I considered a lot of options for the mounting of the bar but in the end settled on one of the simpler options, your needs and tastes may lead to a different setup. The bar comes with L brackets for each side and hardware to mount to a flat surface. I ended up getting longer hardware and spacers with matching washers.
The spacers drop the bar down about a half inch and it fits very snug in the shell. A small bit of the chrome on the upper lip was trimmed in each corner to allow the L brackets through. I taped up everything while I was working to avoid scratching everything to hell. The metal fins on the back of the light needed to be trimmed in the middle to fit around the hood latch support. This isn't a big deal just be very careful about cutting into the cord while working. I held a flat piece of metal over the cord when working near it so it couldn't get damaged.
The finished result is quite visually striking and extremely effective. I no longer have to worry about outdriving my headlights at night.
Low Beams vs High Beams (4HI mod + bar)
Overall, I strongly suggest an upgrade to your lights if possible and have found that LED is quite a good option for doing so. Check out M & R for LEDs of all sizes.
Just another strip or two and your hold front would be a massive beam of light 
