93 Legacy dies at the top of big hills.?????????

Need more info than that, help us out here.

Automagic or manual transmission? How many miles on the car? Is the engine hot or cold? Does it stall every time or just sometimes? When was the last tune-up?

feul preshure or pluged fillter feul pump going d'os it get better if you take your foot out of it ? exhaust smell funny ?

Auto,  dies going up large hills, revs high, no torque,

runs rough for a few minutes after stopping then comes good.

Also known to do this on occasion on motorway.

Any codes or lights on? Like check engine light or AT temp light? Does your motor seem to be the problem or the transmission, it's hard to tell by the way you are describing it.