My only "issue" with the crower 271 in this application is the large amount of split in duration.
It's good with nearly stock heads and the weaker exhaust flow, but edelbrock exhaust ports are much better than stock, and on a smaller displacement combo like a 383 I think there would be a possibility of over-scavanging, although it probably wouldn't be much of an issue with shorty headers and closed exhaust(however tightening that cam to a 108lsa along with the longer exhaust event does create even more overlap, which may not really be your best friend with a less than optimal exhaust system).
Also, the Crower 271 ground on a 108, which is a custom, I'm guessing will cost a bit more than the $127 Competition Products sells that Howard's Rattler for(and is shown as "in stock").