Rs200 Factory Lsd Part Code

[sherpa]

Hi guys. i recently purchased an RS200 with the 6 speed manual gearbox. problem is, i'm beginning to suspect that it was originally an auto and then was converted to manual. I'm not too worried about the 10hp difference on the auto engine but what i really want is the lsd diff. so how do i know if it is an lsd diff other than doing doughnuts? Anybody know the part no for the factory lsd unit? or any other way to check if it is an lsd? your help is very much appreciated