1978 351M Head / Gasket
 

The other day I went to start the 1978 F-150 4x4 351M C6 SuperCab and it took a lil more throttle than normal. So I popped the hood and seen oil all over the place. I seen water contaminated oil at the edge of the left valve cover breather and knew what was going on. Pulled the dipstick to find low level oil contaminated. I added oil to the block and have not started it since. The oil was really centered around the right head. So thinking I blew a head gasket right there at the back where the oil leak is at its worst. I have not seen oil in the water, so hope it's not bad and my head is not cracked or warped more than .006 :-blah

So getting ready to pull the beast into the garage and start tearing her down. I would like to hear some comments, opinions, theories, and tips before I start. First, this just needs to keep the truck going till spring so understand I am not going for good parts, but not trying to fail from the start. Spring time I would love to have the heads machined, ported, polished. And at that time I would like to spend the extra $ to have it reliable for years.

To make it work for the rest of the season I put together a list of gaskets I would need from Napa to get the right side head done.

Head Gasket # FPG 8548PT2 $15.69
Intake Manifold Gasket # FPG MS90361 $11.09
Exhaust Manifold Gasket Set # FPG MS90291 $9.99
Valve Stem Oil Seal Gaskets # SEP MV1796C $0.20 each

I need some of that Engine assembly grease.

For the intake manifold do I need just the gaskets or do I need that formed sheet metal piece that goes in it?

I couldn't find single exhaust gaskets.

I need to figure out which Thermostat Housing Gasket to buy, 3 to pick from. Anyone know which one it is?

Am I going to need anything else?

I have not done much work on engines and never really alone. So I only know some of the basics. I seen I will have to get the alternator bracket out of the way. I can remove the air cleaner and take the intake manifold off with the carb attached correct?

Do I need to use a sealant on the gaskets? RTV or anything or just use the gaskets? I've always used RTV on the valve covers and heads... but not the intake and exhaust gaskets.

And I would like some confidence that those valve seals are the ones I need.

That is all I got so far. Please let me know if you think I am forgetting anything, or doing something wrong. I was thinking I should get a pressure test done, but when I remove the head I should be able to visually inspect for a cracked head, cylinder bore crack or like I really hope just a bad gasket.

I am going to install an aftermarket temp gauge to monitor the temperatures so this does not happen again. I can only guess that the engine started to get hot.

Anyone know how to check the temp sensor? Is it a simple check for resistance? Anyone got the Ohms specs on hand?

I believe the formed metal piece. Valley pan comes as the intake set your list seems fine but I would have the head checked out to be sure it's flat. A hard metal straight edge and feeler gauge is all You really need. Yo fleck for warpage.

There are some cracks that you can't see, have it checked

I would be sure that it's not the intake or valve cover gasket leaking before I tore it down. Could possibly be condensation that you are seeing in the oil.

The oil leak could certainly be from the valve cover. However the water in the engine oil is not a diluted amount. While running there is water blowing out of the vent in the valve cover, drops at a time. I have to say it's worse than I thought so going to get a kit so I can do both sides. I could check for warpage but not incredibly small cracks so I might take them into the shop up the road for someone to take a good look. What is a good price to have them machined if they are warped? And pricing typical to have someone port/polish them if in fact they are a good set of heads? I might use some incometax $ to just get it done sooner and all at once. But there are lots to do to this truck so have to spread the love.

So add power steering fluid to the list.
Is the water pump attached there?
Might as well add a P.S. fluid filter in line somewhere while I got that moved. So much $ whew :-X19


Now I am just guessing since I have no oil in my water but I am low on oil that it blew out all over the road and my chasis.

Is my C6 a 3 or 4 speed because I feel like it revs too high when doing 50MPH. It don't really go into second gear just skips from 1st to 3rd. I can make it manually go 1-2-3 if I use the shifter. Maybe I was overworking the old lady?

Is it "skipping"? If it's actually blowin' that much water it should have a dead hole

What do you mean "skipping" and what is a dead hole?

Hey I just started rebuilding the same truck except its an f-250 and a '79. I got a kit on Ebay from Grumpy's Performance. If you want a camshaft and lifters the compleat kit I got was $355 and it has everything except the water pump. I had my crank sized at napa for $125 and to get everything else pressed in ie. Camshaft berrings, piston rods was about $75 Hope this info helps if you choose to go ahead and rebuild it -JT

I am hoping to pick up another 351M with the purchase of another truck or two. I am going to keep one modern car, and have 3 late 70's Ford trucks. Then I can focus on doing rebuilds. For now just going to pull the heads have them inspected and reinstall them. I dont know what is in this engine, but the cam does not seem stock. I do need to replace the headers. One of them has rust holes, so might put a lil $ in a set. And ideas for budget headers? Thanks for the help, will start working on the truck here in the next week.

I don't have headers on my truck thanks to this lovely CA Smog requirement. I did buy a nice set of low profile porcilin headers for my wife's 302 on ebay a while back though. I don't remember what I paid for them but it probably wasn't much or I woulden't have bought them! Alot of small companies are selling brand new products on ebay through ebay stores now, keep your eye out eventualy you will find what you need. It will be hard to find ones for a 351m though without having them custom made. Try Headers.com. Good Luck!

Put a pressure pump on the radiator and pump it up and see if you can tell where its comming from. Just take that valve cover off if need be. I would be sure where the leak is before I pulled a head.

Dead cylinder

Ok so skipping is the same as "missin"? Or is this different?

I posted up pics of my undercarriage. . . listed as "Rusty Pictures" just in case anyone wanted to see. I can use all the tips anyone has. I love to learn.

Pull the oil drain plug. If there is antifreeze in the oil, it will come out before you see any oil. Also, you should not have to pull the thermostat to get the head off. When I did mine, I pulled intake with carb attached and heads. I am running a 400 but that is the same set up as a 351M. Do you have Factory Air?