Did you happen to change the belt...Good Year Gatorback?
I'm guessing it's more of a mechanical squeal like a bicycle petal that has been neglected for far too long (is that an accurate description?), but I thought I'd mention the belt.
If not maybe this'll help...
I'd also check the alignment on the belt to the pulley. If the pulley is being angled-off center to the clutch it may cause some unwanted contact causing a squeal.