hitkrdnck62571

Hi all, I'll try to keep this short, and really hope I explain things well enough to get some help. Heres the deal, bought a used 1990 f150 with the 300cid inline 6 engine a few weeks ago with the understanding that it needed a head gasket. finally got around to working on it this past weekend, and it is still losing anitfreeze, i believe it is getting into the oil and from there also getting burnt. Now when the truck is started it will run ok for about 5 minutes, then it begins to smoke a little, and another 10 minutes later it is smoking like crazy and the truck dies, and will not restart until it has cooled down. When I drained the oil yesterday, thinking that maybe it was just burning the coolant that was left in the oil from before I got 2 to 3 gallons of oil/coolant when I pulled the plug, and the coolant level in the radiator is still going down. Through further investigation, I discovered that the head that is on the truck now must be from an older model, as there is nowhere for the +/- 1/2 inch line (smog something i believe) that comes from the air pump to connect to the head. My question is this, Is there any difference in the heads that could be causing this problem, or do I have a warped/cracked head or cracked block? Now I know why I'm not a mechanic, get frustrated WAYYYY to easily, any comments/criticism/answers are GREATLY appreciated. Thanks, High Tech Redneck