MSD 82648 Ignition Coil Blaster LS Series, Red, 8-Pack

Exact fit for a 2004 hummer, easy to install. Increased power and fixed an engine fault light. Great product

I own a 2005 GMC Sierra Z71 Crew Cab with engine code T. These ignition coils fit my truck perfectly, and they look great under the hood. I was coming up on my 100k mi maintenance routine and I figured why not, you can get stock replacement coils for less but I wanted something nice. Unless you had a seriously misfiring cylinder, you probably won't notice an enormous increase in performance. But with plugs and coils with unknown mileage on them (that probably needed replacement a bit ago) I did feel a slight performance increase and it seems I'm getting just slightly better fuel economy. I'm happy with them!

I had the rear knock sensor fail in my 05 Silverado and the truck has a 120, 000 miles on it. Since I was going to be taking off the intake I thought I would replace all sensors and ignition components given they were all original equipment. After reading many reviews I pulled the trigger on these MSD Blaster 8264 Coils. The install is simple, just remove the bolts and remove the harness from the coil and install the new ones. They fit with no modification necessary. I am running them with the MSD wires. The truck definitely has a better throttle response. I bought this set off 8 coils on amazon cheaper than I could the factory coils. They came packaged in a huge box all nestled in thick protective foam like precious gems. I have no check engine light issues at all and am running the factory wire harness. I would definitely recommend these coils especially when they are cheaper or equal cost than oem.Update: On 4/23/17 I started to feel a slight and very random misfire. Initially I thought it was bad gas. After running a few cycles of injector cleaner the misfire was still present, but getting worse. The truck started to almost stall out, dumping the rpms after hard acceleration then stopping at a light. Being that I had replaced nearly every sensor on the truck with factory AC Delco parts I decided to run a compression and fuel pressure test. Both checked out stellar. I began to look for ground issues, which are common on these older model Silverados. I cleaned up all ground locations and traced back the wires with no fix to the misfire. After about 6 months of this very random misfire, I was at a loss. The only code that came up was P0300, multi cylinder random misfire. I ran the truck on an oscilloscope and watched each cylinder individually with no real evidence of a isolating it to a single cylinder. At this point I was not happy. When the truck misfired I noticed that the lights would dim. At this point I searched forums for problems with MSD 5.3L coils and came across someone who had a similar experience. It explained that MSD checked his coils and said they were fine but when he got them back he had the same issue. I decided to order a cheap set of Chinese coils to see if they would solve the problem. I found the entire 8 coil set for $87.00 on Amazon. After replacing them the truck is running flawlessly for over a year now. The Chinese set has outlasted the MSD coils and I no longer get the power fluctuations that I had with the MSD coils. In my opinion it may be that the factory wiring harness does not provide the power these hotter MSD coils need and therefore results in failure over time. I came to this conclusion because MSD does sell a harness that powers the coils with a direct 12v feed. Hopefully this helps someone with similar problem regardless of what coils they are using. No codes ever pointed to a coil and the coils were the problem the whole time.

Great product. I recommend over OEM if your looking for a bit more crisp idle and rev.I also put a quality plug in and upgraded from 7mm wire to 8mm

I gained 120 miles per tank under HEAVY load.Highly recommend , but not much of a power difference. It is a bit more responsive but i also put in edlebrock wires and NGK plugs at the same time.6.0 vortec V82003 yukon xl.

Noticed an acceleration increase and they were easy to install

Was getting P0300 misfire, sadly the coils didn't fix it but the truck works a lot less on the highway and improved response. Is it worth the price? Probably not. Have noticed slightly better fuel economy.Update: Misfire was due to something as simple as loose positive cable on battery, fixed and shifts smoother now as well.

2003 GMC Sierra 2500HD 8.1L. Even though it's not listed as fitting on Amazon, it does fit this truck. They look good, but more importantly will they last, we'll see I guess.