i used thin wall steel on the build not PVC, it was just over 1" OD , but yes 1" thin wall PVC is around the same outside diameter as the pipe i used. i made the templates by eyeballing and rough measurements i found on the net for length (it was the best i could do at the time) and just had to guess on the diameter.. if you could make a charcoal rubbing of the original shroud and scan it i could update the templates to a more accurate version