MTU RWIN DSL

Pinging my ISP, verizion dsl , from my Windows 98se on the host machine, I
found the proper MTU to use is 1492. All the internet advice says if using
ics, change client computers to match 1492 MTU. Is it necessary to change
both host nics as well to 1492 MTU, just one, or neither nic? Do XP clients
have to be changed or does the automatic clamping take care of it?

RWIN is another topic with a lot of conflicting info. Dslreports RWIN
calculator provides a different result from the equation shown in the
tweaking FAQ. Dslreports suggest that too high an RWIN can result in packet
loss. John Navas site typically recommennds alot higher RWIN than dslreports
and speedguide.net even higher RWIN values.