You are saying that I only need to cut the 1/2" pipe at the old valve and use couplings? I will be able to slide the couplings up the shower/tub pipes, so that is not an issue. However, you think that I will be able to bend the 3/4" pipes far enough to fit in the couplings in areas marked A and B on the attached pic? I'll only have about 1/2" of copper pipe coming off the 3/4" pipe after cutting off the old valve and another 1/2" coming from the new valve. Is that enough material to get a good solder connection?