Bought a truck years ago with a Magnum Stroker and bought a set of Magnum Valve Covers a year or two ago. I'm wanting to put these on the truck but, I'm wondering if I will need spacers to run the valve covers? The reason for my question is the truck has a different valvetrain. It has aluminum heads with 1.7 Crower Rockers Arms and it has a Hughes Custom Grind Camshaft. Cam is 228/336 @.050, .560/.565 on 108 degree LSA but, I'm assuming those numbers were based upon a 1.6 rocker arm ratio. Anyway, I'm hoping I won't need spacers but, it's some wide style LA Valve Cover on there now. Attached is a picture of the valve covers currently on the engine and another picture attached of the valve covers I'm hoping to use. Thank you in advance.

Could be that the fabbed valve covers/rocker covers are there because of clearance issues.
Do they have baffles inside ?
The critical measurement is most likely from gasket rail to baffle, not sure if that dimension is published on the MP covers.
I suppose you could double up some cork gaskets, but I've never cared for that.
I used to make the spacers, but was losing money on the project.
Medici Mfg makes them now; more expensive, but they're surviving. They're on Ebay as well as directly, IIRC.

Have you taken the covers off yet ?

I haven't taken the valve covers off yet as it winter here and dealing with some health issues but, I wanted to ask before hand. I thought someone might remember if they had something similar. It did have 1.6 rockers prior then they switched to the Crower Rockers and Lifters. If I recall there was guys running the Mopar Magnum ones I think with the Harland Sharp Rockers if I remember correctly. I'm not sure what brand the tall ones on it are now. They came on the truck as you see.

Thank you. I'll have to keep that in mind and refer back to this post. I see that some of the Big Block ones have Baffles inside of them.

Those cast VCs look to have full length baffles same as stock Magnum VCs. They are 10 bolt but the spacing fits 5 bolt heads, I've wondered if that creates leak issues.
Hope this helps