Will my rectoverb head accept these tubes?

[Johnny2Bits]

Well I was playing my amp the other day and saw a flash and the sound cut out, so I hit the standby switch. When I gave the amp a try after a minute channel 2 sounds really muffled and breaks up with the volume only up a little bit. So I'm guessing I blow a power tube. I went to the guitar center to get new tubes. The tubes currently in the amp are 5881/6l6 str425 red 13's. They only had str420's and nobody knew if these tubes would be compatible with my amp. Here's the question, would these tubes work in the amp and what difference in sound is there between the 2? Would they be more suited for modern hard rock like metallica?

 

[ANIMATED SUSPENSION]

If they're Mesa STR420'S they'll be fine. You'll notice more gain and a brighter tone that's for sure.