The 53-year-old found the net 28 times in 73 appearances for the Dragons, while Bale is closing in on that tally with 14 goals.
Ramsey is further behind on eight international strikes, but Rush has backed both players to continue their impressive recent form in order to overtake his record.
"There's no reason why Bale can't, but I think Aaron Ramsey is in that category as well," the former Liverpool striker told BBC Sport. "It's nice having a record but if someone like Gareth Bale or Aaron Ramsey broke it I'll be happy because it means Wales are doing well.
"They are playing more games now and they are young, so I'm sure one of them will break it one day."
Wales currently top their Group B Euro 2016 qualification group, with a trip to face Belgium in Brussels next up.