258 Head

[JimsCJ5]

I am replacing the valve cover gasket the PO decided to glue to the plastic valve cover. I noticed the head has "83" cast into it. I know the head was replaced at one point so is this a 1983 head and if so does this mean I can easily toss the plastic valve cover and upgrade to the cast aluminum cover?
If so, hurrah!

 

[Jimbos76cj]

I think it all depends on the way the valve cover is bolted down.. IF yours has the proper bolt holes for the aluminum cover then go for it.

 

[elwood blues]

Can you post a picture of the entire head, from the top, that'll help.

 

[JimsCJ5]

It's dark now so I'll have to wait until I see daylight at home again which for me means next weekend.
Anyway, I bought a valve cover gasket for a 1979 AMC 258 i6 / 4.2l and it is no where close to being right. The passenger side of the head is straight with three holes for the valve cover. I looked at a valve cover gasket for a 1983 and it looks like the one I need. So I am pretty sure it is a later model AMC 258 i6 / 4.2l head...

 

[mtnwhlr]

The stock valve covers on both my '83 and '84 AMC 258 i6 / 4.2l have no bolts going thru the gasket their is only two studs that go thru the top of the valve cover with nuts.

 

[caveman]

The number that will tell you what year the head is is located on top of the head above #4 cylinder on the drivers side of the engine. Generally you can't put an aluminum valve cover in place of a plastic one unless the aluminum one is aftermarket.

 

[Petescj]

I think it all depends on the way the valve cover is bolted down.. IF yours has the proper bolt holes for the aluminum cover then go for it.

Yup , the difference is that the driver side edge of the head isnt drilled and tapped for the bolts to hold it down. It uses the method stated below.

The stock valve covers on both my '83 and '84 AMC 258 i6 / 4.2l have no bolts going thru the gasket their is only two studs that go thru the top of the valve cover with nuts.

I believe the plastic valve cover started in 1980. I can say my 81 , 82 , 83 and 85 all had them. My 78 didnt. Your Cj being a 79 wouldnt. I think your right , the head is from an 83 however it doesnt help you rid yourself of the plastic one its the root cause.

 

[JimsCJ5]

I was unable to get to work today thanks to Mother Nature so I took a coupe of pics


Ok so what are we dealing with here?
The valve cover I have on it is plastic and has the holes for the 1/4-20 bolts on the flange but also has two holes in the top which are plugged with bolts thru a thick rubber spacer. I am assuming that is not stock...
I've seen some aluminum valve covers that look like they would work.

 

[Torxhead]

That is a late model head and intake manifold. That little screwed in part in front of the carb is a knock sensor that is used to reduce timing in case of pinging or knocking for the computer controlled vehicles. You can remove it if you like as it does not serve any purpose for your application and it does not go thru to the coolant. If you want to re-use the valve cover, I would suggest cleaning all contact surfaces and using a sealer on them, plus the gasket of course. I have not removed my plastic valve cover for about 15 years now.

 

[Petescj]

Sorry about that Jim I may have confused you a bit. Its the driverside of the head that needs to be drilled and tapped for you to use a different valve cover on a later model head. As long as your plastic cover isnt warped and you follow Torxheads instructions it should be fine.

 

[Dep]

I have a question on this. I just had a 1996 4.0 head installed on my 1985 AMC 258 i6 / 4.2l . The machine shop put the old valve cover (plastic) back on it, all the holes lined up and it actually seems to fit pretty good. Am I seeing things or is this normal?