Pulling the head is a rear bear in the chassis. I've done it on other engines but not even on a standard 5.4 let alone a dohc 5.4..
As we've been talking about, it's almost easier to pull the engine if you're going to remove the head. If you have it out then it's a judgment call whether to get another one or two fix yours. Depending on the miles and if yours ran okay before and whether or not you can hear a new one run before they pull the engine. Otherwise you're always taking more risks. I wouldn't have a problem keeping the same engine but if it were out I would remove the other valve cover to make sure all the Springs look good and all the roller rockers look good with no slop or play in the roller bearings. Even if the valve on the bad head side has contacted the Piston it probably didn't damage the Piston. They are pretty durable. Might be a slight scratch or Dent but probably no real damage. You can buy a used head from a junkyard fairly cheaply or take yours to the machine shop. I think you said you knew someone that work there. Just don't go crazy having them do a complete high-quality valve job and everything and put two or three hundred dollars into that head. Just replace the one valve and grind it to the seat and make sure there are no broken valve springs or roller rockers that have bearing slop.
Then, while it's out you need to make a decision about your exhaust manifold gaskets. If yours were perfect and no leaks and you haven't Disturbed decide you were planning on taking off yet, then you could leave them on but they are a known issue on older and higher mileage Fords. It's safe insurance to just replace the gaskets while you have them out but be prepared for at least 3 or four bolts to snap off. I did them on a V10 a while back and I think I had four out of 20 that's had to be drilled out. A couple of other ones snapped off but I was able to heat them and PB blast them and get them out with vice grips but the ones that broke off flush I had to drill and easy out and then run a tap through them. There is a Ford kit and I believe it is stainless but it's all just a crapshoot because even though Ford has switched to stainless stainless is not metallurgically up to the task of being an exhaust manifold bolt but it works better than the factory ones. I just went and got some grade 8 bolts with lock washers and put them in.
It's just so much easier to do when the engine is out for exhaust manifold gaskets and then if you ever have to do one because it's leaking badly in the vehicle.
It really isn't that much harder to pull the engine. You don't even have to remove the hood to do it. At least I didn't on my Excursion.
I did have to let the air out of the front tires though so I can get enough height with the engine hoist to clear the radiator support.
Watch you have all the wires and hoses unhooked you just take the 405 bolts out of the torque converter to flexplate and the motor mounts loose on each side from the frame and then remove, cut, or twist until they snap off, the two exhaust flange bolts for the pipes on each side. You will have to remove the radiator and the fan and the fan shroud and pop off any other accessories like power steering pump for AC compressor that are still hooking the front cover or heads to the car.
It's really not that much more work. You just want to use a very very short one or two link chain from your engine hoist and a short piece of chain to go across the top of the manifold so you can get as much lifting height as necessary. Some people like to remove the manifold so they can get the hoist down lower but it can be done either way.
Once you have the engine out and either sitting on a tire or even better, a Craigslist 35 to $40 engine stand, you will wonder why you ever did it any other way.
As we've been talking about, it's almost easier to pull the engine if you're going to remove the head. If you have it out then it's a judgment call whether to get another one or two fix yours. Depending on the miles and if yours ran okay before and whether or not you can hear a new one run before they pull the engine. Otherwise you're always taking more risks. I wouldn't have a problem keeping the same engine but if it were out I would remove the other valve cover to make sure all the Springs look good and all the roller rockers look good with no slop or play in the roller bearings. Even if the valve on the bad head side has contacted the Piston it probably didn't damage the Piston. They are pretty durable. Might be a slight scratch or Dent but probably no real damage. You can buy a used head from a junkyard fairly cheaply or take yours to the machine shop. I think you said you knew someone that work there. Just don't go crazy having them do a complete high-quality valve job and everything and put two or three hundred dollars into that head. Just replace the one valve and grind it to the seat and make sure there are no broken valve springs or roller rockers that have bearing slop.
Then, while it's out you need to make a decision about your exhaust manifold gaskets. If yours were perfect and no leaks and you haven't Disturbed decide you were planning on taking off yet, then you could leave them on but they are a known issue on older and higher mileage Fords. It's safe insurance to just replace the gaskets while you have them out but be prepared for at least 3 or four bolts to snap off. I did them on a V10 a while back and I think I had four out of 20 that's had to be drilled out. A couple of other ones snapped off but I was able to heat them and PB blast them and get them out with vice grips but the ones that broke off flush I had to drill and easy out and then run a tap through them. There is a Ford kit and I believe it is stainless but it's all just a crapshoot because even though Ford has switched to stainless stainless is not metallurgically up to the task of being an exhaust manifold bolt but it works better than the factory ones. I just went and got some grade 8 bolts with lock washers and put them in.
It's just so much easier to do when the engine is out for exhaust manifold gaskets and then if you ever have to do one because it's leaking badly in the vehicle.
It really isn't that much harder to pull the engine. You don't even have to remove the hood to do it. At least I didn't on my Excursion.
I did have to let the air out of the front tires though so I can get enough height with the engine hoist to clear the radiator support.
Watch you have all the wires and hoses unhooked you just take the 405 bolts out of the torque converter to flexplate and the motor mounts loose on each side from the frame and then remove, cut, or twist until they snap off, the two exhaust flange bolts for the pipes on each side. You will have to remove the radiator and the fan and the fan shroud and pop off any other accessories like power steering pump for AC compressor that are still hooking the front cover or heads to the car.
It's really not that much more work. You just want to use a very very short one or two link chain from your engine hoist and a short piece of chain to go across the top of the manifold so you can get as much lifting height as necessary. Some people like to remove the manifold so they can get the hoist down lower but it can be done either way.
Once you have the engine out and either sitting on a tire or even better, a Craigslist 35 to $40 engine stand, you will wonder why you ever did it any other way.