I've asked on tbdsm, but it's been two days without a response, so I'm going to ask here, also.

Would using a 13/16" piston slave cylinder when my current slave cylinder has a 3/4" piston adversely effect the working of the clutch hydraulic system?

I wanted to rebuild my slave cylinder, but nobody has the right kit, they all give me the 13/16 piston kit when I order one. My piston is all scored to hell so though I do not see scratches on the bore of the slave cylinder, I'm just going to go ahead and give up, buy one of the rebuilt slave cylinders they sell for only 3 times the price of the kit. But if I order one and it's the same dang 13/16's piston, only with a bunch of unneccessary parts wrapped around it, can I use it?

Also, how bad of an idea is it to leave the master cylinder unchanged? I was planning on doing a clutch swap in a few months, sooner if this slave cyl. swap doesn't fix my extreme clutch slipping problem. I was just going to change it then- it's not leaking now, and it's a pain to get at that sucker.