Review on APDTY Manifold Cylinder Avalanche Silverado by Richard Bowens

There is not much literature about these ingenious devices. Specifically in terms of how well they're holding up and if this really is a "workaround" for this common GM problem. I recently bought a used '05 Silverado with a broken right rear exhaust manifold bolt. The others are all rusty and will likely break if I try to remove them. Apparently GM engineers cheated and used weaker bolts. In any event, I received several quotes from local shops across town and the cost of replacing a header with these broken bolts was outrageous. Due to the limited working space, it is necessary to drill a bolt from the cylinder head removed from the engine. Collector $150 + $1000 for labor. And that's just one side! Well, the exhaust leak was imperceptible to my untrained ears. Fuel consumption was normal and the Check Engine light did not come on, meaning the leak wasn't that severe. However, my idle was a bit low at around 500 rpm. My understanding is that at operating temperature the idle should be around 700 rpm. Well I've placed a bet on this $30 unit and so far the idle has improved to where it should be. The engine seems quieter. The installation is not "simple", but doable. The dipstick tube is in the middle where the mounting bolt goes. This is real pain. On the bolts you can squeeze the racket, but tight. I followed the instructions with the correct torque. I'm not sure why, but I'm sure there's a reason for the manufacturer's specific torque rating. Hope this lasts long. I bought all 4 units for the front and back of each manifold just in case. $120 for DIY repairs is MUCH better than $2,000 plus. This truck has clocked up 140,000 miles and I'll be very happy if this cheap and ingenious invention manages to drive another 100,000 with no emissions problems.