Yes, the pipes just push into the heads. I usually use Holts firegum to seal them and to help hold them in place. The early type pipes that went with the wafflebox silencer had a boss to bolt them to the small lug just outboard of the engine bolt. The later long pipes, just have a figure 8 clip to support the rear end and silencer. Unfortunately, it is not unknown for the later pipes to work forward out of the ports.
Regards,
Eddie.