It wouldn't surprise me one bit if the car ran faster with longer collector extension instead of a lot shorter one scope
All the 4 speed cars I drag raced ran quicker and faster with longer collectors, which wasn't suppose to work up shruggy work
Take a set along and test them if and when you can up twocents

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)