GM-GMC: Oil Leak/ Pressure, pan gasket, salvage yard

Question
Harry,
I have owned a 1982 K20 Scottsdale 350 for about 2 years. I recently changed the timing chain. Since then it leaks oil at a considerable rate only when running. Also, I only get around 30 psi when running. Even at highway speeds. I used to get between 45 and 60 at highway speeds. I've changed the pan gasket 3 times, I even put a large amount on silicone on the outside. I can't seem to get the timing cover and pan to mate. Do you think perhaps I should buy an after market pan. I want to avoid removing the cover. I depend on this truck daily and its awful cold out. Any suggestions are much appreciated as I am out of ideas. Thanks for your time. Weston

Answer
Checy used to be famous for their timing cover to oil pan interface.  It was virtually impossible to reinstall the timing cover without removing the oil pan.  Chevy changed the design of the two pieces, but I do not recall when they made the change.
The timing cover is made of thin sheet metal and you may have deformed it when you reinstalled it.  I suggest that you remove the oil pan and the timing cover and try to determine if the cover and/or pan is bent and/or damaged.  You can buy these parts from a salvage yard or even from auto parts stores, such as Summit Racing or Northern Auto Supply.  You should also buy a new oil pump and install it while you have the oil pan off.
Reinstall the timing cover first.  Install the new oil pump and then install the oil pan last.  Your oil pressure may not go up, but you will be able to eliminate the oil pump as  a potential source of the problem.
There is no other remedy for the leak other than repairing/replacing the timing cover and oil pan.