i know there will be a pressure difference between rotors if you run an unequal length turbo manifold but how severe will this pressure difference be? What tolerances are acceptable in calling a manifold "equal length". How bad is it for a motor if the tubes arent equal length.

 

all cast manifolds are unequal length (HKS, Greddy etc) as well as many aftermarket tubular manifolds. its not dangerous per se, it just makes less power.

kenn