If your really wanting to upgrade, we all know big blocks oiling systems leave a little to be desired. I have a great deal for you.
I have a brand new in the box Milodon oil pan # 30931 for a big block A body, and Milodon #21010 external oiling system. The pan cost me $280.00 the oiling system $412.00. I will sell both for $500.00 plus the ride. Saves you over $200 and gives you the best system available. I bought these and have since sold the car.
If interested pm me.