Yes you can. Just make sure you have at least 1004 for the m/b Bios. And while your at it Diamond just released a new Bios and drivers for the Viper 550. I would get those as well. I have the same combo, K6-2/350.
hope this helps....
P.S. - 1 other thing, I had to disable the temp monitor on the m/b, other wise it would lock my joystick every once in a while. It wouldn't overheat by it would hang right at the zone to setoff the internal alarm. The TNT is hot.
AMD64 3200, 1 Gb Ram, ATI 9800xt(256)
AMD 2700+, 1Gb Ram, Geforce4600 VIVO
AMD 2000+, 1 1/8Gb Ram, ATI 8500 (128)
AMD 1800+, 1Gb Ram, ATI 9600 pro(128)
Intel 1.6Ghz (478), 768Mb Ram, 8500 (128)