sp2 diff in the vega

[reg]

Hi,iv built a few ball diffs so know how to build them,but the problem im having with this is after about 3 meets,12 heats,the diff starts to bark,it starts off just when i pull off,then after a few more meets it will start to do it out the corners,its not done up as tight as it will go,but its as close as it can be,i sand my diff plates,use buds balls,AE diff and thrust grease,my slipper slips as it should,i run an LRP 8.5 octa......i run LRP SXX V2 on the lowest punch but run a 22 pinion on the std spur,off the line my car is the slowest,i could understant if it were poping wheelies,would glueing the diff plates,upping the punch and going with a 24pinion help,