If there are no errors now, you need not worry. But suggested is, you have to make sure that any on any SUN machine, you will need to use the correct part-number from SUN.
Meaning, it should be supported as documented. If not, in the long run, you might face any critical issues with your system. Anyway, if you're gonna use this as your test machine, its fine. If you're going to use it for "prod" purposes, you'd better cross your fingers. Is not SAFE to do so with such configuration . First of all, I forgot to ask you, the memory kit part-number is supported for your sun blade and are the DIMMs from the same manufacturers?