Congrats on tackling the rebuild on your own. Input clutch tolerances aren't of much concern because anytime the vehicle is placed into gear they are engaged, they are not a shifting clutch pack.
I'd have to look up the chart that I have to let you know what to open up the clutch feed orifices in the spacer plate for 2nd/3rd/4th clutches.
I have also seen the pop rivet truck done but wouldn't be my first choice. A lot of time local transmission shops will flush a converter for pretty cheap. If you can have the hole that was drilled tig welded shut rather than pop rivet. Torque converter sees a lot of internal pressure and having the opening welded shut would be a better option.
