I bought your Doug Thorley headers for my 1994 JEEP GRAND CHEROKEE in 2017 when we were at SEMA in Las Vegas. They have literally been in the box since I bought them and I'm finally ready to install them. Can you send my the installation papers/tech data on these if able. I also forget if they have gaskets included or not. I cannot wait to hear these! Also, what power gains were seen by merely installing these headers? I have a 3" single exhaust now, with a Catalytic convertor and Magnaflow muffler. Thanks again!