timing chain cover

[1Duster1760]

hey guys, need info on the poly motor and LA motors. Can the timing chain cover from an LA motor be used on the old poly motors? I know there are timing marks on some LA covers and some are flat. Or, I need a poly timing chain cover if they cannot be interchanged

 

[QuickBpBp]

Mopar 318 polyspherical motor and LA 318 interchange

Here is some info that looks like it says they will fit but are not identical..