probably. but new is expensive, so if you're gonna go get a used one, get teh other parts too. front disc brakes will do mroe to aid in stopping than all the added power in the world.

you'll need to plumb in a vac line to the manifold.
check with any parts store to see if they master cylinder is the same for manual and power brakes - it may not be. if different, then you'll need one for a power brake system or else you may glue your face to the windshiled every time yo hit the brakes.

you'll also possibly (most likely) need the pedal to booster rod and the rod from booster to MC.

it is also possible that the rod's pivot point on the brake pedal is different - but there should be the necessary hole on the pedal arm. (power brakes need less leverage)