The timing should still be fine at the 14/34* stock setting.
You might have to play with the idle air bleeds some and bump the idle rpm to 800-850 which is not a problem. A higher idle rpm also reduces the chance of reversion. It is not a problem for the drive as long as you are not over a 100rpms or so. It is not that much of a change in power, and the stock jetting should be fine since Merc sets their engines up rich to start with. Take some spark plug readings to make sure its not going lean, but I think it should fine.
The 525EFI cam will have a slightly smoother idle than the regular 741 on a 112.