Questions come up periodically concerning crankcase ventilation issues.
Here's how Chevy dealt with the problem on the 63 340hp engines and may have relevence to other years, as well.
Also, another mystery solved. I always wondered when and why the block castings were modified to change the oil filler area to the hole behind the timing cover. Note the last paragraph in the cover letter specifying the change over on engine number T 0316, or March 16, 1963.
Here's how Chevy dealt with the problem on the 63 340hp engines and may have relevence to other years, as well.
Also, another mystery solved. I always wondered when and why the block castings were modified to change the oil filler area to the hole behind the timing cover. Note the last paragraph in the cover letter specifying the change over on engine number T 0316, or March 16, 1963.