Joined: Jan 2010
Posts: 9,808
Likes: 1,781
From: Northern California
Bikes: Cheltenham-Pedersen racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.
A spot of clear tape should highlight any near-contact with the arm before it ever interferes with the paint itself.
I had this issue on the non-drive side of my Raleigh Team 753 Technium after I installed early-70's Stronglight cranks on a Mavic bottom bracket.
The left arm has less metal surrounding the taper, so is more-easily torqued to where the arm moves inward towards the chainstay.
I re-installed the arm using a bit less bolt torque and with Loctite on the threads, so I have about 2mm now after also shaving a bit of metal from the pedal eye.