Presuming that's a 15/16ths bore Mk2 Rev2- master cylinder, as opposed to a 7/8ths bore Rev1 Mk2 or a 7/8ths Mk1 unit.
It's a conversion we have done many times, but only required when using the larger Celica twin pot caliper conversion to move more fluid to them.
A bit pointless on a Mk1 with stock calipers to be honest.