My father and I rebuilt my great grandfathers Harry Ferguson, the rebuild went good. Until we put around 30 hours on it we started to here a squeek coming from the valves. Upon further investigation we are not getting oil to the head it was dry we poured oil over the rocker arms the squeek went away immediately. We put a new oil pressure gauge in with the rebuild we are making 40psi at idle when it is cold and it drops down to 0 when we shut it off. We also thought it might be a head gasket problem maybe the holes did not line up. So we removed the rocker arm shaft and blew compressed air down the galley and it sounds like it is blowing into the pan. With the rocker shaft off and the galley wide open we cranked the tractor we made 30psi and still no oil to the head. We really need some help we are both stumped and really want to avoid splitting the tractor again.