I'm curious about the hard felt. I'm using the spray in liner. I have a 2500HD gasser. I'm adding a cast aluminum trans pan with drain plug. The pan on it it has no drain plug. Has a built in digital trans temp gauge and is going to get a large cooler in series with the factory cooler. The 2.8L Colorado has a large cooler and a Derale cooler pan. Just got the GMC Sierra 1500 out of the transmission shop. 3-4 clutch packs burned out at 150K miles and it has a large cooler and a factory cooler. It is a known issue with 4L60E. The bill was $2100. Five GM trucks and a TJ, I must be insane!