what are the differences between the 91-93 and 94-95 2TZ-FE engines?

i'm going to buy a JDM engine for my 1991 previa and there is a naturally aspirated version available, listed as a 1994-95 2TZ-FE (not FZE). how is that different from the earlier years? will there be difficulty or extra labor in the swap? will we have to strip down all the peripheral components, like the intake manifold and EGR?

what exactly changed?

thanks for your help, i really want to get my van back!