Small block valve covers - did something change from 73 - 74?

[MoPar~Man]

When I swapped my '67 Monaco poly 318 (Canadian car eh?) with an unknown-year remanufactured 318 from a Chysler dealership (this was circa 1987) I picked up some aftermarket chrome covers (because the engine did not come with them, nor with an air cleaner or oil pan if I remember correctly). I was looking on kijiji and ebay for old/used small block rocker covers (not a good selection) and came across a set of new / aftermarket covers on ebay (over 100 sold) that claim to be for '67 to '73 small block.

I was curious as to what might have changed on the small block in '74 that would make these covers incompatible.

(I know I must be in the minority here, a C body with a small block...)

 

[3175375]

When I swapped my '67 Monaco poly 318 (Canadian car eh?) with an unknown-year remanufactured 318 from a Chysler dealership (this was circa 1987) I picked up some aftermarket chrome covers (because the engine did not come with them, nor with an air cleaner or oil pan if I remember correctly). I was looking on kijiji and ebay for old/used small block rocker covers (not a good selection) and came across a set of new / aftermarket covers on ebay (over 100 sold) that claim to be for '67 to '73 small block.

I was curious as to what might have changed on the small block in '74 that would make these covers incompatible.

(I know I must be in the minority here, a C body with a small block...)

I have 3 LA 318 C bodies. You are not alone. I don’t know what the change might be.

 

[CBODY67]

Are the covers for a '67 LA motor or the Poly motor? What valve cover gasket does the replacement motor's cyl heads require? The smooth LA pattern or the jagged/offset pattern of the Poly engine family? This might be a situation where you match the pattern and not the model year of the reman engine. NOT to forget "The Canadian Connection"!

Poly and the later LA motor were quite common (the "Standard V-8") in non-Chrysler-brand C-bodies.

 

[volksworld]

big block guy here...but my guess would be going from a push on breather that went on a big tube on the cover to something that installed into a hole with a rubber grommet on the later engine...perhaps a 1/4 turn filler cap too?

 

[scatpack_69]

All LA covers swap, physically, between other LAs. And of course Poly is their own deal.

 

[fury fan]

big block guy here...but my guess would be going from a push on breather that went on a big tube on the cover to something that installed into a hole with a rubber grommet on the later engine...perhaps a 1/4 turn filler cap too?

That would be my guess too, something with PVC fitment, breather, oil caps, etc.
All the LA SBs I've seen have the sparkplug wires routed over the VCs toward each pair of plugs, so I don't think it's the looming/routing.

You could look at Year One and other resto places and see what they show for applications.