hp500 vs. hp525 whats the diff?

[33 Daytona]

I have 2 hp500 EFI's and was wondering what the difference was between my engines and the 525 version. Also can I build my 500's to 525's economicaly. Thanks for any help or suggestions.

[smokediver]

the new 525's have aluminium heads and a closed cooling system. the fuel injection is managed by the merc smart system.. I read an article on those new engines.. I believe it said they make 550 horses..

[Bryan Tuvell 33ZX]

500
http://www.mercurymarine.com/hp500_efi_-_470_hp

525
http://www.mercurymarine.com/hp525_efi_-_500_hp

[33 Daytona]

Thanks. It doesn't look like It will be worth it to convert to a 525. But had to ask. Thanks for the help