The PB160/180 daughter boards will not go into the 140 or 145. RAM expansion cards were differently specified for 140/170 and 160/180 series. Both types will work at least in the 160/180, but the older types may throttle RAM throughput in the newer machines. For the 170 a second video card was available in the form factor of a RAM expansion card. Rarely there were offers for overclocked 180s running at 40 instead of 33 MHz. The early PowerBooks were fast machines in their age, extremely high priced and with few room for improvement (given you chose a top of the line model like the 180).