no oil to heads.

Hi, been lurking for a while and have gotten alot of good info from here. I now cant find an answer to my problem. I have a 68 383 stock rebuild, new everything. oil pressure with gauge showing 70psi. but no oil to rockers. removed rocker assy. and the passage in the head is bone dry. I ran a wire through the passage from the head o the cam and no blockages. pulled motor and tore it back down to check cam bearing, it lines up good on all three holes. ran wire through and no problems, removed crank and ran wire through there its open. al main bearings are correct. everything looks good and the oil pressure never dropped below 50 hot ideling. could the cam be drilled wrong? how do i check that. thanks guys