Good score on that eng . From everything I have read or seen about the heads, It's as good as the classic / vintage inline alumn heads. 
 
 Jeff Jones on the Vintage 6 Mustang facebook page recentley did a comparison of a ported big log modified steel head,the Classic inline & one of the Argentina  heads.   The head bolts straight onto our 200/250 engs with no modifications  un like the Australian cross flow head .  As stated the exhaust manifold  is not interchanagble with our 200/250 .
   If you find you need some exhaust or intake  gaskets it's possible that Jose Alverz on the Vintage 6 Mustang facebook site can supply some . 
    After cranking several small block Ford engs that set for 10 20,&25  years recentley  that all ran excellent, 2 of which I own .  I'd be inclined to oil the cylinders up ,prime the oil system , put it on a stand & fire it up .