Pretty much everything you read is true. I cant add anything that hasnt been said about them already. Anyone looking for a small "cheap" bolt on, this is your answer. No more dead spots, just pulls and pulls through the whole rpm range. With my 5.9, 1.7 roller rockers, 3" exhaust, 3.55 gears, 265/70/17 tires my speedometer is still spot on amd I can cruise 70mph at 1800 rpms in optimal conditions. 80 is around 2200 rpms. And that's an auto 4x4 long bed that weights just over 5k lbs with me in it. Not bad at all.