1965 fastback 306 hci v3-si @10psi Pro M efi. Tko600 3:55
I have the Dynomax VT. It is a straight through design but incorporates a spring loaded valve that stays mostly closed under light loads. No drone whatsoever and the noise level is not bad just driving around. Under load though the valve opens up for unrestricted flow. I dont see them on Dynomax's website now.
Also flow numbers.