hey does any one have any knowledge on the evo 4 RS rear diff, i am looking at upping power form 55whp to 800 and am just looking at some precautionary measures, the diff is in good condition i have had it apart and set it up, i see there are side plate options for the later evos, im wondering if these are required for the earlier evos or even if they make them for the early evos.
i see shot peening is getting popular has any one done this??

anyone seen the early diffs fail? if so where have they failed and why