vacuum advance problem

[mwmeador38]

ok i've got this 66 283 two barrel truck with a carburetor that is apparently not original. it's a holly. the truck has never idled when cold (no choke) and i assumed it was the carb and lack of choke. i have to baby it for like fifteen minutes before i can finally put it in drive. i was fiddling with it tonight and found a vacuum advance problem. the vacuum advance seems fine - holds vacuum and all, but when i try to manually advance the distributor body it's REALLY hard to rotate. the truck has sat a lot but the distributor advance is not frozen or any thing. it's just so hard to rotate that it hurts my fingers to do it. the advance weights open apart just fine. any ideas? is there a spring under there that's way too tight? i've got the idle mixture screw on the holly at max idle and it doesn't help a bit.