My brother bought the comp pro mags for a 94 lt1, and they are to tall for the stock valve covers. The poly locks won't allow the valve cover to go back on. Just wondering if anyone else has had this problem, and if the lt4 covers will work? Thanks

 

The 7/16" 1.6 nsa pro mags I have clears the stoc covers after triming the supports for the bolt posts as required by any standard or non narrow body rocker. The LT4 covers I fitted later are pnp.

 

It's not a height problem, the Pro Magnums are wider and interfere with the support ribs that hold the bolt tubes in place. Remove the upper support (closest to the intake) and the stock valve covers will fit fine.