head gasket i had the same problem with my blazer after my raditator took a crap and blew a head gasket with it. i got it fixed for 800 bucks heads was checked and gasket replaced. i noticed when i had no heat from my vents and checked my oil it was milky and slimmy feeling hope this helps

 

So i changed the intake gasket. And set the time and distributor. Wow, it works! Now it sounds horrible. Computer said #4 cyl. misfire. I'll change the wire and plug, and go from there. Thankfully, #4 is easy to get to. I musta pulled those wires 20 times at the distributor getting it right. lol
So far (20 miles) the oil hasn't risen and looks clean. Maybe i got lucky. But I'll watch for head gasket problems. Thanks, Peace.
New - Sounded horrible because of the blown out muffler. Still have the miss, new plug, new wire, same thing. Maybe debris in the valves? I only changed the bottom intake gasket. I'm at a loss, and now the trannys's shot. No reverse or 2nd. Need to find a used one I can try out.

 

I'm sure you took your time and did a good job. I've blown a few head gaskets in my day and in all cases it was where I ran the vehicle in a severely overheated condition. I'm sure Swartikk has a procedure here to diagnose the miss...just keep your fingers crossed that you didn't plug up one of the injectors or bent a pin on the injector control block.