I've got a '79 250, 400 that I discovered coolant was leaking in the rear passenger area...it also trickles down when sitting. When it runs, it gives out white smoke constantly. I looked at the freeze plugs, and they look fine.

Is it safe to say the head gasket is shot? If it is, how do I go about replacing it? I have never torn into an engine before. Is it a straightforward process or must I prepare for major surgery??

Thanks for the help, guys.

 

I would guess from your description that yes, you are dealing w/ a blown head gasket. Depending on how mechanically inclined you are the head gasket is not that hard to replace. You will have to remove the intake manifold,exhaust manifold, valve cover, pushrods and the mentioned head. Most info on how to do this can be found in any repair manual for your year truck.

 

sometimes it's easier to disconnect the downpipe and pull the X manifold with the head, then separate them out of the truck if you really need to.

 

Seems like a lot of work for a gasket.

so I'll need a new intake gasket and exhaust gasket along with the head gasket.

It doesn't have any options, so the only thing under the hood is the engine and standard accessories. It won't be difficult to work around...only my inexperience.

I read the factory Ford repair manual. Looks like the push rods can be left alone when removing the head? To remove the push rods, I have to remove the rocker arms first. Or will they fall out on the other side if I left them in when removing the cylinder head?

At this point, I'm only worrying about the exhaust bolts. I don't have anything beyond a breaker bar and PB Blaster.

 

I did the head gaskets on my truck in about a weekend, with no experience and just hand tools.
Make sure to soak those exhaust bolts, and plan on a couple snapping off in the head. Just don't try to use an easy-out on them, let a shop drill them out for you.
If you can find someone to help you lift the intake and head up and out of there, it'll make life a lot easier and you won't end up busting your dizzy or one of the ported vacuum switches (heavy intake vs plastic parts never ends well).
You'll need to remove the rockers and push rods, put each set into a plastic bag, and mark which cylinder they go to. That way you should just have to torque them down when putting everything back together.
Oh, and expect to make a mess under your engine. When you loosen up the head, it'll dump coolant all over.
I'd recommend you change both gaskets out, while you've got her torn down, and make sure you install the new head gaskets the right way (just double check the old one before you take it off the motor.

Sorry, I know all of this might make it sound like a bigger job than it is, but it's really not. It's just a lot of heavy parts. Figured I'd give you some fair warning on some potential hazards, as I had none when I first did mine, by myself, in a dirt lot in the summer heat with no shade.

 

that's why i suggested leaving the manifold on the head. draining the coolant from the block drain plugs can help reduce the mess, they might be tough to loosen without heating them up first.

 

The intake gasket is a simple steel metal pan, as long as you don't bend it you can probably re-use it. If you decide to get a new one, use the Fel-Pro one, and follow the directions exactly.

 

ihatemin, that's great advice. Now I won't be so worrisome. I'll try to leave on the exhaust manifolds so I don't have to deal with them...needs new exhaust, though, so perfect time to ditch the rusty pipes and dual it out. I'm going to change the coolant out anyway so fluid won't be an issue.

And thanks for the advice, guys. I ordered the gaskets for everything I might need as I'm tearing into it. Now all I need is a lot of time. I shouldn't have too many problems, albeit it will take a while to do the whole thing.