Hey guys, i am in desperate need of aluminum valve covers, but i cant find them anywhere. I have a 90 Iroc, so i assumed i would need the stock centerbolt valve covers, but instead, the previous owner replaced the heads i think, and now i cant find valve covers that are the same as the ones on there.

The ones on them right now are perimeter bolt. On the right valve cover (if you are looking from the front of the car) has the oil fill hole and the pvc hole. On the left, there are two holes, one with something in it, and one thats just empty. Its hard to explain... here are some pics...

Right side...


Left side...

More of the left side...



I went to two speed shops today and everyone who looked at my car was baffled. First, they wondered why one of the holes was empty, and then they couldnt find any valve covers in their parts catalogues that looked like they would fit.

As a last resort, i thought i would come to people who know irocs the best... u guys. Can someone PLEASE point me in the right direction here. Where can I get these valve covers or ones that will at least fit properly. A link, advice, anything would help.

Thanks in advance!

 

yea one of those holes should most definitely not be empty unless its sealed off or something. I don't see why those valve covers are any different than any other valve covers ever made for chevy heads. Or am i missing something?

 

Yeah, they look like standard chevy valve covers. On the other side, you should have another pcv valve. The other hole needs to be plugged.

 

On the driver-side valve cover, there should be an oil fill hole and the PCV valve hole. The PCV valve connects into your intake manifold (that looks correct, judging by your picture).

The passenger-side valve cover should have only a crankcase ventilation hole. This should connect into the throttle body on TPI systems. That also looks correct. I think that the extra hole is just a plug for another application, like maybe a breather.

Perimeter-bolt valve covers ended in 1986. Therefore, the heads are either 1986 or older OR there is a centerbolt-to-perimeter-bolt adapter on the heads (probably unlikely). The intake manifold design also changed after 1986. Therefore, you'd have to have an '86 or older TPI manifold. But you're also running a speed density airflow system, which didn't debut until 1990. Go figure. Realize that this only applies to GM parts; aftermarket is completely different. It's very likely that a set of aftermarket heads, with perimeter-bolt valve covers, that bolt to a post-1986 intake manifold is on your car. Either that, or you have a mixture of parts from many eras.

Any perimeter-bolt valve cover should bolt up, it's the question of whether it has the PCV and crankcase ventilation holes that matter. I would check GM Performance Parts and see if there's an OEM solution.

 

Those are the nastiest pair of valve covers I have ever seen on an engine that actually runs. It does run right? Whoever owned that car before you probably couldn't open their own hood!

Anyway, you should be able to use any kind of perimeter valve cover you can find. Be careful of the tall ones though, you may run into clearance issues with the alternator charge post. Mine is very near on my covers, centerbolt though.

I am surprised that a parts guy at a speed shop was baffled by that setup. It is not factory correct, but its not really odd either. They should have been able to sell you a pair of $30 chrome covers from behind the counter...

 

Thanks for all the replies guys... lo and behold it does indeed run, but I still would like to replace the valve covers.

I figured any perimeter bolt valve cover would work, but as Blue86Iroc said, the problem is finding one with the oil filler and pcv hole. I cant find it anywhere, I looked through the edelbrock, moroso, and gm perfromance parts catalouge and found nothing at all.

Can someone show me where to find one of these valve covers with the proper holes. I desperately need new covers as many of u have noticed, so any help would be greatly appreciated. Thanks again for all the help so far...

 

You will just have to have the holes drilled into the valve covers you choose. It is a common problem, especially with aftermarket covers. Be sure to have grommets installed, too.

The oil filler hole may have to be aborted and you might just have to use the pcv hole to add oil. Common, again.

They did all this with a set of Chevy big block covers on this weekend's Horse Power TV.

 

Those are just stock VCs off of some 70s car, before they started putting the wiring tab things on them. They do look a bit sad with no paint and all that rust and all.

I don't understand about "desperate need for aluminum valve covers".... never seen such a thing before, like the car won't run with steel ones, or whatever..... but I can about guarantee 100% that any aftermarlet valve covers you get, you will have trouble of one sort or another with. Looking for ones with the correct PCV hookups is very smart on your part. Especially with MAF TPI. Finding ones that not only have that, but also include effective baffling underneath them, is even harder.

The ones I like to use are the Vette L98 ones; they're perimiter bolt, cast some kind of metal (some people say magnesium, I don't know), with ribs like the old Vette VCs had; correct baffling, correct oil holes, correct PCV hookups, they fit and work right period. You can get them from about anybody that deals in Vette parts. Check with www.corvettehangout.com and see if he has any.

 

Looks like you just got 2 right-side or 2 left-side VCs (can't remember which has 2 holes) instead of a left and a right. Thats why you have 4 holes.