Fenderwell cutting templates !
Here's a few close up pictures from my '65 Barracuda of where Hedman Husler 75110s enter the fenderwells. I believe it would be the same on your '66 Valiant. The #1 and #2 pipes require cutting down closer to the frame rails and that can't be seen in these photos. Assuming you install these pipes individually, those cuts can be rather small.
Here's a few close up pictures from my '65 Barracuda of where Hedman Husler 75110s enter the fenderwells. I believe it would be the same on your '66 Valiant. The #1 and #2 pipes require cutting down closer to the frame rails and that can't be seen in these photos. Assuming you install these pipes individually, those cuts can be rather small.
