Did you check the head for warpage? You may have to get it milled. A
Going to try to this morning. I have a short Starrett rule that I'm going to try to find and use. It will be irritating to have had the head come back from the shop un-checked and un-milled, after I paid for a rebuild.
cheap (universal) head gasket could also leak. I had this problem on a Datsun truck.
That Victor Reinz gasket _wasn't_ cheap! -- Jim