What chainring combination are you using? The smaller the size difference, the narrower the horizontal spacing should be. You should be OK with any standard "8-speed" chain, such as an SRAM PC-58, but, as others mentioned, do avoid 9- or 10-speed chains.
Also, check the length of your chain. 24 half-links should measure no more than 12-1/16".
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069