sounds like the exhaust housing is too small. with it's restriction the turbo is more efficient at taking exh energy and driving the turbine. you vacum reading seems real low for a stock cammed motor. mine runs around 12 @ highway speeds, 15 @ idle. hits zero at just about any throttle push part 1/4 and then boost pressures. i would get rid of the pcv, clean up the hoses ect. do you have power brakes? if you do i bet they won't work very good. get the pv closed and readjust the idle mixtures and you will see more vacum. tom
