Not on this forum, but elsewhere I've read of those problems for over 10 years now and they're always the same. Gasket cracks, gasket blows out, falls out, breaks apart, etc. Some have said they believe the gasket becomes internally damaged when you install it...but you may not know it for a while. From what I've read, too little torque and they fail, too much torque and they fail...some saying if suggested torque was 20, then use 10 or 15 but in no case use more than that. And in my opinion that's a low number for a manifold for which GM said use 30~35. Recently on a Subaru forum a poster said he followed the instructions and they worked great for a while and then 3 out of 3 failed and others chimed in saying they had the same issues. And then there are always people who think these are the best thing since the polio vaccine.
But as I said I've never used one so I'm on the sidelines watching. If I look back over the years there have always been products that claimed to be what everyone needed for this or that. Magnets on the fuel line to increase your gas mileage. A special screen that goes between your carburetor gasket and manifold to increase horsepower. Ball bearings you put inside your tires to keep them perpetually balanced. Things you pour in your gas tank to "rebuild and revitalize" your engine. All snake oil and sideshow stuff.
Coilover's comment took me a moment to find. It was:
https://www.stovebolt.com/ubbthread...remflex-manifold-gasket.html#Post1352245 My feeling is if it worked for Evan, it will probably work for anyone else.
