[1972GMCsierra4x4]

I found a set of very lightly used Dart angle plug heads on CL for $550. They have the 2.02 intake valves, 1.90 exhaust, and 76cc chambers. I have heard good things about Dart heads and I thought this was a pretty good deal, but I figured I'd better ask around before shelling out the cash. What are y'all's opinions