You can buy a Chevy distributor or another way is to use a Ford Duraspark II style distributor. They were used in the late 70's and early 80's.
Available in junkyards or on eBay. Cheaper than the option above. You need the distributor and the control box.
One other thing, shakin66 - you need to make sure you have the right distributor gear. Some of the newer distributors have a steel gear, but those are only meant for the newer roller cam motors.