Replacement Drivers for Monitor 7s

Easy Runnin
Easy Runnin Posts: 501
edited August 2013 in Vintage Speakers
I have a pair of M7s with 6500s. I might be able to get a good deal on some 6503s. Would the 6503s be suitable backups for the 6500s? I don't know if it makes a difference, but I have peerless tweets.
HT- Samsung PN50B860/Integra DTR 30.3/Rt55 Fronts
Rt35i Surrounds/Cs1000p Center/SVS BP1000 Sub
2CH - B&K MC-101 pre/B&K EX-442 amp/NAD 2400 amp
Polk SDA1C, Polk Monitor 7, New Large Advents and Polk RTA 8T
BR - Yamaha CR800/Polk monitor 5