I ordered a Derale transmission pan from Summit thinking I would finally be able to fix my warped leaky transmission pan issues. I was wrong. The model I got had a quart and a half extra oil capacity and soem nifty little cooling tubes in the bottom. So feeling like a little kid on Christmas morning, I tore in to the box and at first glance was excited, but on further inspection my excitement turned in to disappointment. The first thing I noticed was the bottom of the pan was caved outwards. This kind of perplexed me so I started checking the mating surface and it looked like soemone grabbed the pan at both ends and tried to twist it.
So back in the box it went and made a call to Summit and they took it back no problem. In conclusion I would say to steer clear of Derale products, they suck.