Help with 348 Cam Seal Housings

Hi all, just starting to build up my cylinder heads back up from a valve job.
I have removed the cam seals from their housings and found 2 out of the 4 housing have had a “notch” ground into them ?? Any idea why this would have been done?. It does not look like it was done at the factory.

What do you think ??
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Better oil drain away from seals. Make sure the notches are on the bottom when you reassemble. Early heads also have a smaller drain hole away from seal area which a service bulletin said to enlarge.

 

Thanks for the reply, so shall i grind the other 2 then ? what you think

 

I would, but that's me....
Also, maybe drill out the drain hole in the head a little larger.,,IIRC, they should line up.

 

Is your car an 89 or 90? By 1991 all four had factory installed grooves. Use a sharpie and put a mark across from them so it can be seen during re-assembly. Install with the grooves at the lowest point or sharpie marking at the highest point. Doing the other two would not hurt anything but it is usually the exhaust cams seals that have the leakage problems. Don't forget to pre-coat the sealing surface with assembly grease.