Sylvania 5881 vs TungSol JAN-CTL 6L6WGB tubes

Are these tubes electrically similar? TS tubes are manufactured in 1961 (code 5960-262-0161) and Sylvania 5881 tubes in the 80's (code 8026 ADG 34167). As far as I know, the TS tubes have a rated anode dissipation of 23 watts and a maximum anode voltage of 360V, but I don't know Sylvanias' characteristics. With an auto-biased amp, is it safe to replace Sylvania 5881 tubes with vintage TungSol tubes? I did it once bit one TS tube produced an arc and one fuse blew. The manufacturer claims that it would be safe to use TS tubes if they are OK. Unfortunately, I don't have a tester to check the TungSol tubes