Because of the increased compression...the engine blocks are made stronger to resist all the internal forces. Also, no real ignition system means more reliability. I'm hoping that this low mileage, the motor is just getting at a break in point and should give me many trouble free years ahead.
The "half-cuts" are the way to go versus just getting a motor/tranny and wiring harness. We stole a lot of little goodies off that front clip to make the transplant go smoothly. Frankly, I don't know what we would have done if we didn't have the whole clip. I have since been able to sell a lot of little bits from it too which helps to recouperate my investment.
The conversion from RHD to LHD had very little to do with the motor and tranny. The biggest issue is lengthening the engine wiring harness. There are about 40 wires that have to be lengthened 30", that took the better part of a day with a soldering iron and heat shrink tubing. Other details were minor dash trim in the conversion of the auto to the 5-speed. The shifters were bent the wrong direction and the trim pieces are all bass-akwards. The pedal assembly also did us no good so a LHD one was fitted. We were able to source most of those parts from a local toyota wrecking yard.
Wiring was the biggest hurdle. I lengthened the main harness but I ended up hiring an automotive electrician to sort out all the other details and even he said it was not easy. He had to splice a ton of things into the main chassis wiring harness behind the dash and that looked like a rats nest of wiring... that was $700 well spent IMHO!