The owner of this Midget put a lot of thought into which engine to pick. As his website states he wanted something that would still have the feel of the original engine. After much debate he finally decided on a 1991-1995 AE101 4A-GE “silvertop” which comes with 5 valves per cylinder and individual throttle bodies. The choice for this engine came because of the huge amount of support and information on these engines. The owner makes a point you can get one of these engines with harness and ecu for $600 from http://www.venus-auto.com. This swap ups the hp rating from about 60 hp original to about 150 hp post swap. If you are interested in a swap like this I would check his website out. At the bottom he lists links to sites and people that helped him out a lot.
Source: Jalopnik
Want to put Toyota engine in my midget