High idle problem

I was reluctant to post this question because I feel like an idiot but after swapping my intake I cant get this car to idle below 1500 rpm, Ive checked for vacuum leaks and it seems to be good, set the timing to where the car starts perfectly (like it did before the swap) and played with the idle mixture which brings it down initially , slightly. . Any ideas? this thing is driving me crazy. eddy 600/eddy D4B.