Probably ought to find the online manual on this ... Braingears.com or something like that...

You do need to match the valve adjusting top nut with the camshaft or the cam follower ...don't remember which one offhand...
on the 616 engine there is an ' uprated' engine and the regular... the first has a few more hp .... and got it with higher lift lobes...
there are chilled cam lobes and something else... try to find the online manual ... but hollar if you can't and I will try to find my manual...