1st Transmission Removal - TH350

[Quint]

Hello Gents, it's been a while! I mostly lurk around the page reading threads and taking advice from others that have came before me. But now I have found myself in a predicament.

Back in Febuary I bought a 1962 C10 stepside with a 383 stroker and TH350 automatic tranny. I also drove across the country from Alabama to Arizona to pick up a rather rare utility bed for this truck...which is a very special project of mine. The truck had been turned into a drag truck - lowering spindles, they cut the rear springs decided they weren't low enough so they heated them and let the weight of the truck compress them further. My first order of business was bringing the truck back up to stock height, which went smoothly.

Well, while going down the interstate at 60mph the truck all of a sudden started revving real high. I pulled over and discovered that the TH350 tranny would not engage forward or reverse. So, I had it towed back to the house.

Later that night I started the truck, let it get warm and checked the fluid in the tranny and it looked a tiny bit low, so I added some and let it warm up. I had the back on stands, so I can test it. When I shift from Park to Neutral - nothing (good) then into Reverse - nothing (what the hell?) then in to Drive - nothing (SOB). I've came to the conclusion after a bit of reading that what is possibly wrong with the tranny is that either the converter or the pump went out.

And here we have come to the crux of my current problem. I've never pulled the transmission out of this truck....let alone any vehicle.
So, my question to you all is: how do I do this? Is it really as simple as drainging the oil, taking a few bolts out, and disconnecting a few things, or am I simply overthinking things? Oh, I will be doing this in my garage on the floor.

Does anyone here have experience in removing a TH350 tranny from a 1962 C10? Is there a thread on the forum that I possibly missed? Any advice? Can I simply remove the transmission or do I have to pull the engine and trans?

Would it be smarter to swap the trans over to a TH400 since it is already pretty stout or just build up the TH350 to handle the 383 Stroker?? Truck pictures are from before I raised it back to stock height.