The stock 340 cam from 71 is essentially the stock 360 cam from 72 on...and the actual difference between the stock 318 cam (.390 lift) and 340/360 cam (.410 lift) is so minute as to not be an issue. Either cam is going to run out of snot long before 5500. Use your stockers and don't look back.
...Oh, and try to put that cam up about 4 degrees. You need all the advance you can get with that low squeeze 318.