so i recently did a z32 rear brake conversion on my 240 to match the set in the front and the caliper on the drivers side rear is rubbing against the rotor and i cant seem to figure out why? i rebuilt the calipers but it seems one of the caliper pistons isnt engaging fully and it isnt seized. so im thinking it is an issue with not enough pressure, will upgrading my stock BMC and brake booster resolve this issue? i have been unable to find anything on this online so i am curious if anyone has experienced something similar. (pics below)
https://i.imgur.com/VBHKyGb.jpg
https://i.imgur.com/SJ7HNQi.jpg
https://i.imgur.com/32D4jkf.jpg