Hi John,
They are the long Dynomax Super Turbo Mufflers #17749. I have a Pipes 2-1/2" exhaust system. I also use Turn Downs at the tail pipes. They take the tinny sounds away..
Would you mind telling me what mufflers you are running on the car with the Crower 60919 installed? I have listened to the car on YouTube and really like the sound of it and am considering installing that cam in my '65 GTO.