My Permacool filter had stampings on the top labeled "In" and "out".
MAKE SURE IT IS PLUMBED CORRECTLY!!!!!!
I know, I fried a transmission the other year a week before my trip to the Dragon. There is a check valve that won't allow reverse flow. I plumbed it wrong as was amazed how low my tranny temp gauge was staying. Of course it stayed cool because there was no flow....
