Civic EG

So I got 96-00 Integra rear trailing arms, they've got rotors and calipers, and the ebrake lines, can I use the stock EX Master Cylinder and proportioning valve?

Yeah theres no reason why you cant use them, they'll work fine but a bigger m/c will improve your braking and the correct prop. valve will lessen the risk of the rears locking up, but youd have to be really trying to lock the backs up anyway

Its a good idea to upgrade the m/c and change the prop. valve but its not essential

Okay, well I'll get the brakes on first then replace those two on down the road I suppose.