GM crossram intake-valve cover interference

[VintageMusclecar]

What's the trick to get a set of OEM cast Z28 valve covers past the base on a GM (repro) crossram intake? It appears the valve covers will need "massaged", but I don't want to do that unless it's absolutely necessary.

Eric

[Jeff H]

The factory manifold has a small area machined just above the ports to allow the clearance. I'm guessing the repo manifold doesn't have that machined area.

[VintageMusclecar]

Jeff;

I see what you're referring to, but the problem I have is the valve cover won't even go between the (factory) rocker arms and the "lip" on the base where the top plate bolts on. I tried to snap a pic of the area I'm referring to, but that didn't go so well.

It's definitely looking like I'll have to remove the lip on the top side of the valve covers if I ever want them to go on.

Eric

[plumL78]

You will need to trim the edge of the valve cover. You have to trim them with a real gm crossram intake too. I believe you will have to cut about .060-.070 off the covers

[VintageMusclecar]

Kerry;

Thanks, that's what I figured.

Eric

[DarrenX33]

Whoa whoa, put on the brakes….

You should have that machined area on the repop manifold. Having a crossram is a maintenance nightmare. The manifold and valve covers (namely the drivers side as I recall) have to be put on at the same time. No cutting needed. However, like I said when you need to adjust your rockers its a little more work than just removing the valve covers.

Your intake gaskets too thick?

[VintageMusclecar]

Darren;

The repop intake has the machined relief just above the ports, but that isn't the area of interference--there will be enough room there once the valve cover makes it down that far.

The problem is that valve cover is binding up between the pushrod side of the rocker arms and the lip on the manifold base where the top plate bolts down. The only way they're going to fit is by finishing the factory partial reliefs on the tops of the covers the entire length of the upper edge.

I'm really appreciating the simplicity of a good ol' single 4bbl dual plane manifold right about now.

[plumL78]

If you don't trim them you can't get them back off with out taking the intake off. Valve covers come off a bunch more times than the intake needs to.

[VintageMusclecar]

Now that my "assistant" is back home and I have a 2nd pair of hands available, I managed to get a pic of the problem.

[plumL78]

Eric you may want to buy a set of the later covers. As you see in the pic. you neet to cut past the notches that are in the covers. Mine is a real GM intake and I've al ready been through these problems years ago