Hi Stepho,
I don't know much about the ST162 Corona because we don't have that model in my place.
This is actually my second 3S engine. The ST150 Corona originally had a 1S (1800 cc) carburatored engine. Then about 7 years ago, I dumped in a 3S-GE from the Celica ST183. The engine mountings were identical except for the gearbox mounting had to be moved a little forward. The ones on the rear of the cross member was also moved a little. Other than that, everything was done without much mod.The most difficult part was to make the dashboard fit into the Corona body.
This second transplant was more difficult than the previous because the Celica ST202 is overall bigger in dimension than the ST183. So making things fit into the Corona was kinda nightmare ! So other than the engine & gearbox mountings remained untouched, almost every other parts won't fit. Even the radiator's bigger & taller. The exhaust manifold is only a few millimeters away from the radiator. The fans from the ST202 could not be used because of their size. Old fans from the ST183 has to be used.
The dashboard was the the major issue. That held up the project the longest. So to simply put, it's much more challenging than the first project.
It just doesn't make sense because when we first look at it, it was anticipated as a plug & play job; that is until we got our hands dirty...