ACCEL140040ACC SuperCoil Ignition Coil - Yellow - Individual

Bottom line first; these were not a direct bolt-on fit, I returned them, so I do not know if they would have resulted in the advertised increase in horse power (10) and increase in fuel efficiency.Depending on which website you go to you will get conflicting information as to the fitment of these coils. My application was for a 2004, Chevy Silverado 2500, 6.0 liter. Many sites said these would fit, some said they would not. They did not. Come to find out, there are at least two types of mounting brackets for GM engines. More particularly for the LQ4 engine in my truck, these coils (140040) are for an older style bracket, with the mounting holes orientated horizontally. My truck has the holes orientated vertically. I searched for the coils using the engine information vice the vehicle’s. So I ordered the Accel 140043, direct bolt-on for my LQ4 engine? Nope! I needed to go to the hardware store and purchase 0.5inch spacers and 0.5inch longer bolts. These work great; increased throttle response (horsepower/torque) and increased fuel efficiency (2-4mpg), exactly what I was looking for.If you are looking for aftermarket coils for a GM product… be sure to check the brackets and part numbers. I found the brackets for the 140040 coil, but chose to purchase the 140034 coils instead.

The fitment was off on the mounting holes and after installation on a 2002 chevy suburban 5.3 flex motor 5 of them were throwing codes and engine was stumbling put back on stock problem solved looks like a good solid product just did not work in this application

Arrived on time, near perfect replacement part. needed some minor repositioning of the mounting clamps to match existing hole placement.

Great Buy and fast shipment

Started having trouble with coils failing one after the other within 6 months . Only had one month return window. A lot of money for a bad product.

These were installed on my 2006 Chevy Express 3500 with the 6.0. Within a week, one coil had to be replaced. Within two weeks, two coils had to be replaced. I am now heading to my parts store to see which one(s) have failed now more out of curiosity than anything, because they have only been on for 3 weeks and I’m done changing coil packs. So, I will be looking at other brands to replace them all.

Great replacement part