Timing cover replacement

[Dakar Timm]

Due to the serious leaking of coolant from what I believe was between the block and the timing cover,I removed
The water pump and timing cover .
The coolant passages from the block appear to have been eaten away . I’m familiar with dissimilar metals corroding .
The motor in question is a 318 Polyhead .
Are all the timing covers the same for the small block ? How much deflection is acceptable for the timing chain ?
I figure in for a penny in for a pound .
It appears the gasket no longer had the surface it needed . Thanks

 

[MoparLeo]

Timing chain play ? Really? You are in there, just replace it now. The new tensioners might also fit.

""
Parts That May Be Interchangeable

• Crankshaft: An LA 318 or LA 340 crankshaft can be used in the Poly engine.
  
  
• Timing Cover, Water Pump, Harmonic Balancer: These components can look similar enough to appear interchangeable and may bolt up, though specifications should still be verified for your specific engine.
  
  
• Early LA Dampers: Some early LA dampers can be used on the Poly. ""