I am just wondering what a set of Valve Covers off of a 50's Olds Rocket engine might be worth.

 

You don't specify which engine. If they are for the 303 ci. and have the spark plug wire covers with decals, you should be able to get$75 to $100.00 depending on the condition. The 324-371 ci. with two bolt holes, $25.00-$35.00. The W1 option J2 covers with dimples for adjustable rocker arms, $200.00 The chrome dimpled covers were after market sold by Isky cams. The non chrome dimpled covers are factory original W1 covers. I hope this helps you.

Dr. Oldmobile