Strange oil leak

Truck: 1994 c1500 5.7, 85k miles, original engine, regular maintenance.
The truck sat for a few days, moved it maybe 20 feet to readjust its parking position and I noticed a fresh oil leak stain had formed minutes
afterwards, about 4 inches wide. Got under the truck and found oil dripping off the large crankshaft pulley, and nowhere else. Would this be the front 'main seal' leaking? Any info would be appreciated, i.e. ballpark cost-to-fix figure, possibility to fix in my garage (plenty of tools here), etc.
My daily commute nears 200 miles so I am going to park it until I get this fixed. Thanks for any info.
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Easy fix, pull of the harmonic balancer, timing cover and change the seal. Make sure there is no groove worn in the seal surface on balancer. If so get a seal with a sleeve for the balancer. Don't forget to lube the seal or it will burn up in 2 sec.
Good luck

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Replace timming chain and gears at the same time
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It could be the front of the oil pan gasket leaking as well. Before you go ripping shit off like others have suggested, hose the area down with brake parts cleaner or any aerosolized degreaser, let it dry, then watch it like a hawk to see EXACTLY where the oil is originating from.
Doc

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