That's some "need to know" information. I think the pressures are going to have to be a little higher in the transmission to handle the torque of a big block chevy. I'm sure Dave can fix you up with a spring and boost valve setup that will meet your needs. What valve body are you using. I would think with a CR valve body and governor the transmission would shift a little early with 3.42 gears.
Currently have only a CR valve body, which is on the trans, and an OG, which from my research was one of the worst to use. I actually bought a pair of these trans. The one I rebuilt(the CR), which was original to the sellers car, he had played with the t.v. trying to get harder shifts and ended up with a slipping trans. The other(the OG) he had bought rebuilt and installed and drove it 3 weeks with it slipping on shifts, until it had lost all gears. I dropped the pan on the OG first, because it was so clean on the outside, but the fluid that came out of it was black and is the worst smelling fluid I had ever encountered. There was so much clutch material in the pan it looked like mud. The CR was very clean inside, didn't smell burnt at all, the fluid was bright red. The only clutches I found burnt were the overrun clutches. The steels were hot spotted as well. The rest of the clutches had almost as much material as those I put in.
