MR_STIFF_GODZILLA

hey guys i have a 1990 r32 gtr i have a bit of a issue i dont know what to do or where to go my front cv boots were on there way out the left one outter boot was stuffed and the right inner was gone to and i only drived it on the weekend. the issues i have was when i had it awd it would make a clicking noise from the left hand side when i would give it shit in first in second not the typical signs like turning (it never made a noise when doing that only when i was trying deliver the power through and go in straight and only if i full locked it while trying to reverse it would make a big clunk noise ) so the plan was to buy complete front drive shaft set from nissan because i was having trouble soucing new boots for it and most cv places wouldnt touch it . so in the mean time i would drive it in rear so not put stress on the front . it would never make a noise or clicking when it was in rear . for a while i left it in the shed for 6 months to do work on it and worried about doing any more damage to it . long story short i started driving it again but left it in rear and didnt put it in awd due to the cv problem ,recently i put it back in awd and took it for a drive now im getting a center clicking noise its not a plesent noise in any way i thought it might of been my center bearing but that is fine. what im wanting to know is that has any one had any simular problems and if any one could help me out with any info at all or places to take it to (perth region ) or wat to do:) the mods list is to long but in a short way to explain everything has been modified on it besides the internals on the motor and gearbox she is running 440hp in awd and 520 in 2wd drivetrain mods :my front diff is a mz 1.5 way cusco dif with 4.375 front and back dif gears, orc 709d twin plate clutch and running 275/40 tyres on 17x10 rims dont know if that would help but i thought id put it in there i havent had problems before that when i use to drive every weekend only after i took her off the road for the 6 months and then started to drive it again on the weekends . regular services on it but havent done a diff or gear box service on it for 4000kms doesnt leak any fluids or anything never let me down tilll now thanks for your time and hope it makes sence and hope i can get help with this issue thanks