Why advance timing?

I was running a vacuum advanced distributor and it (vacuum advance) went bad, I noticed my temp was going higher and I unplugged my vacuum advance and set the timing myself and it went back down to normal, know I have a recurved distributor that does not require a vacuum advance, I had it set a bit to high and my temp went up, I brought it down to 33 degrees full in, set it with a digital timing light at 2.200 rpms and it has ram perfect, yes your vacuum advance could be leaking and not doing it's job..