Help figuring out what valve cover

[mattp1788]

I just bought a rebuilt motor for my 79 well I go to put on the valve cover and I see that it is different then the head... Can anyone help me figure out what year this motor is and if its not a 79 I will send it back!

 

[Petescj]

Im not real familiar with 70s 258s but I do know that they had a different valve cover configuration than the 80s version. Alot of the 80s engines came with a plastic valve cover. The head had a straight seat on the passenger side that had the webing for bolts in the cover. They werent used though. Heres the plastic cover on my '83. Looks alot like yours if you focus on the two bolt area you showed.

 

[CDT540]

Check the casting numbers. I am going to try an attach a doc that might help.

Chris
'83 CJ7 (AMC 258 i6 / 4.2l 4spd)
Austin TX

 

[RubberDuck]

If your bolt pattern is different, it is likely for an 81+ CJ, in which case you will want to get an after-market billet aluminum valve cover that is made for that block. I wouldn't mess with a plastic one unless it came on the motor and wasn't leaking. In my experience they are a pain in the *** to get torqued up right.

This also isn't the most scientific way, but most pre-81 258s I've seen have been painted blue, whereas the post-81s were black, but if this was truly re-manned, they could have painted it anything.

 

[mattp1788]

Thanks guys for the info I did find out that I needed a newer model valve cover!