FWIW the 1400 can indeed run MKLinux, and therefore About any older linux PPC distro.

I have personally installed Debian Sarge, on the very 1400 I am on now [with sonnet G3 466 cpu] No more problem than putting it onto a non g3 1400... No Less Problem either.

I am now running , Happily, OS9.1 on this G3 1400 and 8.6 on the "stock" model 166.

I did Not find Debian to be worth the Effort at all. YMMV

RP