I'd say it depends on how you expect to use the tractor. If your going to really work it hard then match components to the original hp setting. For occasional use, medium loading, rarely pushing it you can probably get away with the higher hp setting without problems.
Would you be kind enough to post the 3H1690 instructions, again.
I have gone back and read that you had posted these - but the file does not show up.
... Or point me in the direction of where the file is.
Thank you !
Per your request....