The TSB states 6-19-68. If it was done prior to this date there would be NO reason for the TSB. That’s very clear. The service addition is very different from the factory mount in how things are attached. I cant’t tell you why the AIM shows one thing, but dated at the tail end of 67, you can bet it didnt happen till later in the model year. Survivor Cars I’ve documented as late as April had no provisions for any of the seals and baffles. Late June / July do. Surprised nobody has commented on the other link I posted in our Restoration section. We beat this to death back in 2007….
Steve