235 oil question

[62 Barnfind]

My 235 in my 62 isn't oiling the rocker right. I am only getting oil to the rear half of the rockers. Oil pressure is 40psi at the gauge. I already cleaned out the rocker rail and blew out the line. I an getting air pressure all the way around to the oil filter when I blow air in the hole on the head under the oil tube. Is there someone that has had this problem? It was working ok until I went on the test drive. When coming back it died and when I stopped I was having valve train noise. Any advice would be great!