4.2 Cylinder Heads and Valve Covers

Could someone please set me straight regarding correct cylinder head color and valve covers. What is the correct color for '67 Series 1 cylinder head? I've been told that cylinder heads painted gold indicated high compression heads. I've also been told that gold was used of 3.8 L engines and that 4.2's were silver. What's the REAL story. Also, regarding valve covers, my '67 has finned covers. The motor is from an XJ6. I assumed the finned covers came with the XJ6 motor swap. Were finned covers limited to XJ6's. I've also been told that 4.2 XKE's had finned covers and the 3.8's had smooth. A couple of sets of smooth covers came with the car when I bought it. I actually like them better than the finned but I want to be accurate. I know what your thinking, "You've got an E-Type with an XJ6 motor and your worried about accuracy!!" Yeh, but it also has the the 3 SU's :)
Mike in West Virginia
60 TR3A
67 E Type OTS
74 MGB GT
76 and 77 MGB
80 TR7 Spider