I agree, I bought a TH350 Tranny that the pan and dipstick seals were leaking horribly, and I used the doorman dipstick seal about 5 years ago and a filter kit with pan gasket, the filter is literally like a screen on most even the high quality ones so if you replace that too theres not too many differences on that particular tranny. But for the pan try and get the rubber gasket, the only problem I had with those was that every time I used one I had to re-torque it after about a week, I believe it's around 12inch lbs but when the rubber gets hot it's very walkable, and it can leak, but if it's tight you probably will almost never have one leak, the cork ones will almost always leak, my pan was even a bit bent but it still comformed after a re-torque, but acdelco is another good brand also just as said, it's basically factory original design with exception of some updates, but some of there products are the exact factory part, BTW I wouldn't recommend etc but slot of people use it and have a real good experience, I just find it messy and un necessary if a good quality gasket is used, and stay away from synthetic fluids, they're not much help on that trans and it will leak like a sieve, but other that that you should be good, the doorman ones are or were around 2-3 bucks I think and the filter kit was like 7 bucks plus fluid, all from O'Reillys, AutoZone would be good too though, just watch the brand's, some are good though, and if it's not a problem to wait there is a bunch of great acdelco stuff online between rock auto and Amazon for decent prices sometimes.
