Center vs: side oiler

[Anthony]

Originally Posted by double ugly

Is the difference between center oiler blocks and side oiler blocks just how they are drilled? I found a side oiler engine block that hasn't been drilled to be a side oiler and is represented therefore as a center oiler. Sorry about the stupid question. Thanks.
John

The original center oiler blocks did not have the appropriate casting for drilling "side oiler" oil galleries. Later on, after Ford came out with the Side oiler design which also had the appropriate casting for center oiler galleries as well, Ford used this casting for some 427 blocks but drilled out only the center oiler oil galleries. many of these engines were used in marine/industrial applications. You can drill out one of these center oiler blocks into a side oiler, but have it done by somebody who has done it before.

Also, as the engine mount pad is machined into the side of the block, in the same location as the side oiler galleries, I have heard that when ford machined these engine mounts into the side of the blocks, sometimes they machined them too deep, and then used these engine blocks that were to be drilled as side oilers and instead druilled them as center oilers. The moral to this is that some the side oiler blocks drilled as center oilers may not be able to be drilled out as side oiler.