Best headlight bulbs for 1989 GMC K1500.

[Rtlane]

Are the Sylvania Xtravision the good bulbs for these trucks? What others are recommended? My headlight housings say "Guide Halogen" on them if it helps.

 

[df2x4]

Sylvania XtraVisions are good, Philips X-tremeVision are the brightest on the market but not as many stores stock them so you might have to order them. If you want something even brighter you can slightly trim the tabs of some Philips 9011 and 9012 HIR bulbs so they'll fit in the 9005 and 9006 sockets. Although I would not recommend doing this with a 9012 in your low beams unless your headlight housings have glare shields over those bulbs. Factory 9006 have a painted glare cap on the bulb glass, 9012s do not.

All that said, if you haven't upgraded the headlight wiring harness then you're not going to get the full potential from any of these bulbs. I'd recommend doing that before you worry about buying the best bulbs. You'd be surprised how much of a difference reducing voltage drop at the sockets makes. @5vortec7 makes a plug and play upgraded harness with 4-Hi mod.

EDIT - I just realized you have an '89, so pretty much none of this applies as you most likely have the sealed beams instead of the composite housings. Sorry! Upgrading the wiring would still be an excellent idea though. Here's a link to 5vortec7's thread where he sells the harnesses.

https://www.gmt400.com/threads/hd-headlight-harnesses-w-4-high-mod.45669/

 

[PlayingWithTBI]

^^^X2 on the 4-high mod.

 

[kennythewelder]

X-3 on the 4 high mod, and add another relay, for the low beams where they are running directly off if the battery.

 

[Rtlane]

Sylvania XtraVisions are good, Philips X-tremeVision are the brightest on the market but not as many stores stock them so you might have to order them. If you want something even brighter you can slightly trim the tabs of some Philips 9011 and 9012 HIR bulbs so they'll fit in the 9005 and 9006 sockets. Although I would not recommend doing this with a 9012 in your low beams unless your headlight housings have glare shields over those bulbs. Factory 9006 have a painted glare cap on the bulb glass, 9012s do not.

All that said, if you haven't upgraded the headlight wiring harness then you're not going to get the full potential from any of these bulbs. I'd recommend doing that before you worry about buying the best bulbs. You'd be surprised how much of a difference reducing voltage drop at the sockets makes. @5vortec7 makes a plug and play upgraded harness with 4-Hi mod.

EDIT - I just realized you have an '89, so pretty much none of this applies as you most likely have the sealed beams instead of the composite housings. Sorry! Upgrading the wiring would still be an excellent idea though. Here's a link to 5vortec7's thread where he sells the harnesses.

https://www.gmt400.com/threads/hd-headlight-harnesses-w-4-high-mod.45669/

I just bought the truck about a month ago and had no idea you couldn’t change the bulbs. Lol One of my low beams went out is why im trying to get some opinions bulbs. So would it better to upgrade to a different housing so I can replace the bulbs or stay with the sealed beams. If the latter, then whats the best sealed beams to get?

 

[98chevy2500SS]

x4 on 4-HI mod + HD headlight harness from LMC.

LMC also sells clear headlight housings for 88-89 trucks that replaces the sealed beam so that you can replace just the bulb instead of having to replace the whole housing: https://www.lmctruck.com/1988-98-chevy-gmc/cd-1988-98-custom-headlights-150mm

 

[df2x4]

I just bought the truck about a month ago and had no idea you couldn’t change the bulbs. Lol One of my low beams went out is why im trying to get some opinions bulbs. So would it better to upgrade to a different housing so I can replace the bulbs or stay with the sealed beams. If the latter, then whats the best sealed beams to get?

In your situation, personally I would go grab a Sylvania XtraVision replacement for your stock sealed beam and call it good. If you want them brighter, upgrade the wiring.

 

[PlayingWithTBI]

LMC also sells clear headlight housings for 88-89 trucks that replaces the sealed beam so that you can replace just the bulb instead of having to replace the whole housing: https://www.lmctruck.com/1988-98-chevy-gmc/cd-1988-98-custom-headlights-150mm

The last time I looked at them they were out of stock. I wonder how they look installed? Personally, I like the sealed beams look over the 90+ composite lenses (plus they don't fade and yellow) but, these LMC ones might be the answer.