It's not my statement, it's the transmission industry's standard of comparison, it's called the "K factor", it's what they use to predict converter stall.
The truth will depend on how accurate a comparison of engine torque between you and the 350 model they used. If your engine develops more per inch (a milder cam and smaller ports will do that) it will be slightly higher, etc.
I don't know if that RPM is what you want, my 3,600 lb. car's transmission with a small L6 stalls at 2,600, and it suits me in traffic.
