Hello,
I have a 1977 Corvette with an L48 engine. Today it is fitted with Holley valve covers that have seen better days (purely visually, think they're in good shape otherwise). There is also some oil gathering around the covers over time, suggesting the gaskets are nearing their end of life (or is this just normal?). I want to do something about this, but am unsure about exactly what. I have a pair of spare original valve covers. I've been thinking about painting those and putting them on the car, alternatively take the Holley ones off, clean them up (they're bare aluminum and would probably look like new with a bit of polishing) and putting them back on again. With this in mind, I have a few questions:
1. The Holley valve covers are taller than the original ones. For me that is a bit of a pain as the alternator almost hits the valve covers (I was JUST able to put a new alternator belt on the car with a whole lot of stretching). I've also seen that a lot of aftermarket valve covers are marketed as "Tall style". Is there a reason why they are taller and will it impact performance or anything else if I put the original ones back on?
2. There is one hose running into each of the valve covers. The gasket around these are not looking good. It seems the magic word I'm looking for is "grommet", but there are so many options! Are they the same on the left and right side and any considerations when buying new ones? I had a look at Eckler's Corvette and I can get some generic ones or one that specifies "left". However, there are no "right" ones. Very confusing! Last, there seems to be an option between PCV and steel, what's the difference?
3. I am replacing the gasket, is there anything else that might break while I take the valve covers off? As I live in Norway any Corvette parts take a long time to get shipped and since the car is 43 years old I kind of expect everything I loosen to not work when I put it back on again... So I have to order everything I need up front unless I want the car to be undrivable for a month.

Hope the questions aren't too basic and appreciate any help. :-)

 

1. I too have the tall covers. They are used when a taller rocker arm nut is involved which requires more clearance between rocker adj nut and cover.

You have to get the ALT belt length just right. Too short and the cover strikes the ALT. Too long and you are at the end of your adjustment on the upper bracket.

2. New V.C. grommets can be had from Summit if they ship to Europe. Std size I believe is 1 1/4". PCV valves come in plastic or stainless steel, whatever your fancy. Some are specific to the engines vacuum in inches. Others are not.

2B. When you order V.C. gaskets, don't skimp on price. Those $9.99ers will come back to haunt you. They crack & leak easily. Look for FelPro blue composite around $15-$20.
When you are ready to "glue" your cover gasket, wire brush the V. covers inside lip with Acetone. Apply a good Permatex RTV to one side of the gasket only for now.
Install gasket on cover, install four bolts to align gasket. Turn cover right side up on work bench, place a weight on the cover and let set overnite. I RTV only one side of the gasket so V. cover removal is easier later. You can RTV both sides if you wish.

 

Everybody else puts L-82 valve covers on (when available) why not you! LOL

https://phoenix.craigslist.org/evl/p...095983691.html

https://phoenix.craigslist.org/evl/p...083516282.html

 

Thanks. Guess I'll know once I pull the valve covers off if I have tall rocker arm nuts or not. Is there any particular clearance required or can I use the original valve covers as long as they will fit without using force?

Thanks for the tip about gaskets, I found some $19 ones that (if the description is to be believed) seals better and doesn't break as easy as standard ones. Shipping and tax processing is the real cost for me, so for cheaper items like gaskets I'll gladly pay extra if there's any benefit. They didn't have the FelPro, but as I'm ordering other parts as well I want to get it all from the same place and Summit doesn't have all that I need. Again, due to the shipping and tax it is a lot more expensive to buy from two different places than one (a $20 gasket will cost me a total of $81 by the time it reaches my doorstep).

 

Basically, Valve Covers come in two heights. Standard and tall. When using after-market rocker arms with two piece nuts, they generally are higher on the rocker stud. So a std ht rocker cover will never clear that nut.
Some, like myself, just like the look of tall, cast aluminum covers. Some covers, like mine, have oil drippers underneath to collect oil mist and drip the oil on the rockers. That would be another plus for tall covers. But there is always the fitment issue with the ALT.

 

Ahh, my mind must have been somewhere else, meant to write valve covers, not headers (I'll correct that now)!

 

The shipping cost to Europe is ridiculous. Three times the value of the product.