hosnoopy

The chamber you have is a normal pipe the WTC chamber has a shorter front cone.

I run my WTC setup 10mm back from were the O rings leek giving a length of 15" from the outside of the port. This is on a self mod 26zen running a MW3 just drops of pipe in a sharp turn.......

Running a normal chamber on a WTC header will give you a 16" pipe length at the least.

Go as short as you can without letting the O rings leak were the bend has been formed..

Running smaller props would need shorter lengths gepending on your setup. Good luck