How hot does the fluid in an automatic transmission usually run or average? How much pressure (psi) is created inside the trans and trans lines? I have access to 2 wire hydraulic hose and AN fittings. I know that the hose and fittings are good for 250-300 degrees in an industrial setting and up to 1000-2000 psi continuous. I am using an external trans cooler. I wanted to know if this stuff would work, because i absolutely despise the metal brake line stuff.  

Based on an Olds service manual the highest reading is 160psi at 1200rpm, I'm guessing it is regulated not to go much more than that.  Temperature much above 200*F isn't good for ATF.  I know most aftermarket Trans coolers have rubber lines and are quite sufficient.  Standard parts store Transmission line hose will be sufficient. If you really want to take it to the next level get power steering hose, it is stiffer and rated for a higher pressure and temperature.  

Full-throttle line pressure on most T-400's goes about 150-165 lbs. Units modified for competition will have more. The relief spring determines the max amount, and the modulation circuitry adjusts part-throttle pressure. Remove the modulation circuits--like with a manual valve body--and all shifts see full line pressure. Normal temps are 190-210 or so, but "loose" converters/hard usage will at least temporarily raise this a lot more. Pan temps over 240 will degrade the fluid rapidly. Pressure in the cooler lines is a lot less than line pressure.  

thanks guys for the feedback.