904 Transmission Stopped Going Into Gear

Well, that's good to hear because you're going in a lot of wrong directions. Unless your "master" kit has selective thrust washers, it's filled with a lot of useless parts. I buy core transmissions for $50. I wouldn't pay that much for yours unless it had a partial throttle kickdown valve body. You don't really have a good core to start with. With fluid you're already looking at $400 for your build. That's just nuts for a slant six 904. The pump cover should be the same price as the direct drum. But more to the point, with that twisted line killing lube pressure, you basically have a pile of junk there. You must look closely at every single wear point, and I'll bet you find a lot more damage. A good used slant six trans is usually around 150-200 and that includes a good converter...and you don't even have to buy fluid. I read threads like this one all the time and they serve to discourage most beginners from rebuilding their own transmission. A 904 is the easiest transmission to rebuild, but starting with that one is a recipe for disaster. Oh, I'm sure it will work, but who knows for how long. If you miss one little thing, it's all for nothing; and that trans was extremely fried so I'm having doubts that you'll be able to find every single flaw. There are 904 rebuild kits on ebay for under $60; with steels and free shipping. You want to spend an extra $70 for a band and some bushings. Buy another trans. Or two.