Can I exchange just top of mast?

Question
I have 440 mast 220 + 220, I need 490, someone told me I change just top
Is it true? does it matter the make of mast?

Thanks
Andrew

Answer
All the mast center connection diameters I've seen are different. I already tried this on several masts.  I got lucky on one that fit with a shim but it is highly unlikely the connection diameters will match. If you are changing the tops from the same manufacturer of masts that were made the same year you can call the maker first to see if they will fit.