Hy Guys, in my parts book p/n 3941316 does not start to be used until 1969, I also checked the engine front mount which also changed in 1969. I believe the correct p/ns for the mount for your application are
Plate group 0.027 3896341 [1]
Mounting group 0.027 3890298 [1]
Retainer group 0.029 3891200 [1]
hope that helps