Here's another question I have. How common is the elbow that goes in the valve cover to connect to the open element AC? A.I.M. has part #3923260 for Z28 open element page 473 UPC Z28 A5 also page 483 ZL2 A3 has it for RPO L48. So was there no difference in the connector (elbow) use? At least I'll know what to look for if I have to find one.