1965 Valiant brake woes
I'd take all that crap out and set it up stock as a 67 with a dual chamber manual master cylinder. My wagon and my 66 vert and every other valiant I ever had got set up like this and always worked well with either 9 or 10 inch brakes .There is a member here ,I think he is called mobile parts .He's local to me here in LI , NY . He sells the good ,imposible to find asbestos lined shoes. When I put those in my car was 1000% better. I can lock up all 4 wheels with 9 in drums now. With the modern shoes it barely stopped and forget locking up the wheels.