Yeah, it will fit but they are not torque monster motors. My son and I put a turbo 2 motor in a 1st Gen RX7 about 250hp. Never really got it 100% done before it was stolen. The police found it last week minus everything and smashed up.
In a 914 you will have to do a really nice radiator as they get really hot. The intercooler too should be a challenge.
Geoff