Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
If the block has had the main saddle aligned honed, the seal bore will now not be the correct fit in the block.
There are two seal diameters available.
You made need this one:
Tiny bit of sealant on the outside, and the parting join, and stagger the joints.
Also ensure your oil leak is not coming from the rear camshaft plug.
Hope this helps.
I hope my advice has been of assistance to you.