air conditioning

Hey guys, I just bought a nice R-12 and R-134a compatible AC manifold gauge set. I noticed that the low side service port on my '86 appears to be a 1/4" and the high side accumulator port is 5/16". The fittings in my kit are 5/16" F. Does anybody have a link to where I can buy an adapter...

Currently my car is always blowing hot air on the inside but the lines are ice cold coming from the compressor. What could be causing this issue?