I have 66 C-10 6Cyl that my Dad bought in 76 and do not remember it ever having a shroud on it. Also it is worth noting that there is another hole in the frame for the motor mount brackets that was used for V8 trucks to move the engine forward. Using these holes gets the engine closer to the radiator and gets the distributor away from the firewall, very important if your V-8 has an HEI distributor.
