Valve cover plug off question

Isaiah Estrada

Isaiah Estrada

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These are Cal Custom valve covers for a big block Mopar. They’re going to be sweet on my 440!

314EE6CC-4DF8-4D07-A105-27CE72F9FDFC.jpeg


I plan to have these polished to a chrome like shine before going on.

The top one is the passenger side and the bottom is the drivers side. It’s a little confusing to see that they have the PCV hole cut out on this side while also having a provision for running a breather cap. I bought a twist on style PCV valve that I want to run on the passenger side, which is where the PCV was originally on the factory valve covers on my 68.

67A25F65-3ED4-4110-8CCA-11452E1DACD8.jpeg



What can I do to plug off the extra hole on the drivers side ? I will be fabbing up some baffles to have tig welded inside too to prevent pulling out oil. I appreciate any help.

A good thing to note is the hole fits a standard valve cover PCV grommet part number 2536926
 
PCV in the round hole. A solid oil fill cap in the half turn hole and a half turn breather in the other valve cover.
 
Where the PCV and breather are really make no difference. Our '66 Newport 383 has the oil filler/breather on the lh side and the PCV on the rh side. My '70 Monaco 383 has the oil filler on the rh side front and the PCV on the lh side rear. As long as they are on opposite sides, that's all that matters, basically.

NOW, if you consider crank rotation, it might be that one side for the air intake and air exit (via PCV) might be better than the other, possibly.

To me, the MAIN ISSUE with aftermarket valve covers is that the PCV must be baffled from the open crankcase air (which can contain oil droplets). Just as factory steel valve covers are baffled with either a simple piece of metal under the valve's intake or an enclosure. Why is this important? Any oil which the PCV sucks out will equate to "oil consumption" and lower crankcase oil levels. Over the years, I have observed others who went with the aftermarket covers to suddenly have an increase in apparent oil consumption, when it was not going past the rings or valve guides, but from the PCV itself. They should have a PCV baffle to screw into the inner side of the valve cover, available separately.

In about the 1972 model year, Chrysler went to their "tall" breather on the rh rr side of the B/RB motors, which filtered air (from the outside of the air cleaenr housing) with an internal filter. A better filter than the oiled hogs-hair filter in their earlier breather caps. With a "flame arrester" baffle on the bottom where it goes into its valve cover grommet.

Understand, too, that any polished aluminum, unsealed, will need to be "maintenanced" to maintain that finish. PLUS wiping them down after any engine washing (or possibly driving in wet conditions) to keep water spots from being on them, too.

Enjoy!
CBODY67
 
The flow through the system is governed by the cfm of the pcv item. NOW, GM did a research paper back in 1961 on crankcase ventilation. In one test on their plant security vehicles, which only saw 15mph at best with lots of idle time, the one with two pcvs had less gunk in the crankcase than the one which had just one pcv, which had much less than the road draft tube engine. So they went with one pcv of a particular cfm (which I now suspect is a universal amount of flow, used by all engine OEMs . . . except the 1970s Chevy L82 small block V-8, which has one with a hair more flow and a purple color on its metal areas).

Moroso (or similar) used to have a "pan evacuation system" which used two of the tall Chrysler (1972+ model year) breathers hooked to fittings in the collector area of the engine's headers, to decrease crankcase pressure and such, for better performance. No PCV items, just "pan evac" functions.

Just some thoughts,
CBODY67
 
I just noticed - those valve covers won't fit on any post 1963 Mopar B or RB cylinder head - they only have 4 bolt holes. All Mopar B or RB cylinder heads after 64 have 6 bolt holes. And, the post 64 valve covers are swappable side to side. So, if you're really intent on using those very nice covers, you may need to drill for the other bolt holes, if that's possible.
 
Ross Wooldridge said:
I just noticed - those valve covers won't fit on any post 1963 Mopar B or RB cylinder head - they only have 4 bolt holes. All Mopar B or RB cylinder heads after 64 have 6 bolt holes. And, the post 64 valve covers are swappable side to side. So, if you're really intent on using those very nice covers, you may need to drill for the other bolt holes, if that's possible.
Click to expand...
^This^

The plus side is that may make them more valuable to someone with an earlier engine. You won't be able to drill the holes needed and I'm not sure if you placed these on later heads if they would cover the two holes on the ends. I don't think they will. You may have more chance of developing leaks without the outer bolts too.

Best bet is sell and buy others if you are set on having that type of valve cover.

It's too bad, I really like the no name covers if you are going to run aftermarket covers.

EDIT: Just checked eBay and yea, the earlier covers seem to be going for more $$.
 
Last edited:
So, it looks like you are in a win-win situation. Your valve covers are the hard to find style and look to be in great shape. You can likely sell them for more than enough to buy another (later version) ones. Yu might even be able to find a set without the hole punched out.
jus sayin.....
 
Ross Wooldridge said:
I just noticed - those valve covers won't fit on any post 1963 Mopar B or RB cylinder head - they only have 4 bolt holes. All Mopar B or RB cylinder heads after 64 have 6 bolt holes. And, the post 64 valve covers are swappable side to side. So, if you're really intent on using those very nice covers, you may need to drill for the other bolt holes, if that's possible.
Click to expand...
Big_John said:
^This^

The plus side is that may make them more valuable to someone with an earlier engine. You won't be able to drill the holes needed and I'm not sure if you placed these on later heads if they would cover the two holes on the ends. I don't think they will. You may have more chance of developing leaks without the outer bolts too.

Best bet is sell and buy others if you are set on having that type of valve cover.

It's too bad, I really like the no name covers if you are going to run aftermarket covers.

EDIT: Just checked eBay and yea, the earlier covers seem to be going for more $$.
Click to expand...

Photo is a bad angle! Now I kind of wish they really were 4 bolt valve covers :lol:

584A3D7F-868F-4E99-9E3F-65B3230793FA.jpeg


You can see the other bolt hole sticking out the other end (kind of.) First pic was just a bad angle!

Also had a major brain fart yesterday thinking these only went on one way… Had a lot on my mind but of course still trying to get car stuff figured out LOL. I finally popped the big question to my now fiancée and the brain just wasn’t quite functioning right :poke:
 
I agree with you about the no name design too @Big_John … True, I dig the Mopar performance valve covers but everyone’s got them! I like the cleaner, uninterrupted design of these Cal Customs.

We’ve got a few welding shops / engine builders in town who can easily weld the hole up and make it look like it was never there. Think that might be my best bet in the end!
CBODY67 said:
Where the PCV and breather are really make no difference. Our '66 Newport 383 has the oil filler/breather on the lh side and the PCV on the rh side. My '70 Monaco 383 has the oil filler on the rh side front and the PCV on the lh side rear. As long as they are on opposite sides, that's all that matters, basically.

NOW, if you consider crank rotation, it might be that one side for the air intake and air exit (via PCV) might be better than the other, possibly.

To me, the MAIN ISSUE with aftermarket valve covers is that the PCV must be baffled from the open crankcase air (which can contain oil droplets). Just as factory steel valve covers are baffled with either a simple piece of metal under the valve's intake or an enclosure. Why is this important? Any oil which the PCV sucks out will equate to "oil consumption" and lower crankcase oil levels. Over the years, I have observed others who went with the aftermarket covers to suddenly have an increase in apparent oil consumption, when it was not going past the rings or valve guides, but from the PCV itself. They should have a PCV baffle to screw into the inner side of the valve cover, available separately.

In about the 1972 model year, Chrysler went to their "tall" breather on the rh rr side of the B/RB motors, which filtered air (from the outside of the air cleaenr housing) with an internal filter. A better filter than the oiled hogs-hair filter in their earlier breather caps. With a "flame arrester" baffle on the bottom where it goes into its valve cover grommet.

Understand, too, that any polished aluminum, unsealed, will need to be "maintenanced" to maintain that finish. PLUS wiping them down after any engine washing (or possibly driving in wet conditions) to keep water spots from being on them, too.

Enjoy!
CBODY67
Click to expand...

All good info, thanks! I did plan on having whatever shop welds that hole up to also install a baffle. Been doing a lot of research on the subject and your knowledge confirms it! I appreciate all the help my friend!
 
Isaiah Estrada said:
I finally popped the big question to my now fiancée and the brain just wasn’t quite functioning right
Click to expand...
Congrats! And figure on your brain not functioning quite right from now on!

Pretty girl too! I wish you the best!

Mrs. Big John and I just celebrated 19 years of marriage yesterday (personal best for me LOL)
 
Big_John said:
Congrats! And figure on your brain not functioning quite right from now on!

Pretty girl too! I wish you the best!

Mrs. Big John and I just celebrated 19 years of marriage yesterday (personal best for me LOL)
Click to expand...

Thank you pal!!! It means a whole lot. Yea, sometimes the brain feels fried but thankfully she keeps me in line LOL.

Happy anniversary to you and Mrs. Big John! We had a couple people tell us that that was their anniversary too! It must’ve been a great day to propose…

LocuMob said:
Congratulations on your engagement!
Click to expand...

Thank you!

1970FuryConv said:
Congratulations on your engagement. Marriage works. Me and the Mrs.: 29 years and counting.
Click to expand...

Thank you so much! So happy to hear you and the Mrs. are going on 29 years and counting strong!
 
Just my 2 cents, some elbow grease and some "0" steel wool followed by some "00" steel wool might make a huge difference in the look of these and save you from paying someone else to polish
 
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