Noise when clutch is released. Help

[jrthe1]

I have a 66 with 327 and I believe a Saginaw four speed. Recently I began hearing a brief moaning noise when letting the clutch out in first or reverse gear from a stand still. As an experiment I started out in second gear and it does it as well. This happens more when the engine is cold. When not in gear and clutch is let out there is no noise whatsoever in neutral. Once moving, no noise in up shifting to 2nd, third, or fourth or down shifting. The clutch is smooth with no chattering. Per PO the clutch was replaced about 10K miles ago. The trans is noisy in 4th gear. Kind of a howl or moan that changes frequency with rpm but I've been told Saginaws are noisy.

Wondering what the problem might be??? Any ideas? Any input would be appreciated. Thanks.