Engine options to go into a 91 Applause

G’day from Melbourne.

i’ve picked up a 91 Applause to use in a charity drive in September it works out the car is just in too good a nick (body, interior) to go into a semi off road rally plus the engine has been diagnosed with a hairline crack in the outer block. So, considered that finding these engines whole (minus auto trans) is almost no existent in Australia. I was wondering obviously with some work what are other possible options of engine to put into an applause if any?