It's a 1900cc 8R-C.
Just like a 2000cc 18R-C except a little smaller inside

Looks like you have an RT80L.
Good reliable cars.
The mechanical part of the transplant is easy.
Any W50 gearbox that used to be behind an 8R, 18R or 20R will fit.
Donor cars are Celicas, Coronas and pickups from roughly 1970 to roughly 1980.
You can also use the W55, W56, W57 or W58 from behind the same cars after 1980 but you may need to customise the gearbox crossmember.
They all accept the same drive shaft that you have now.
Caveats:
Gearboxes from different models have the gear stick coming up in slightly diuffernt places.
You will have to measure where the transmission tunnel hole is in relation to the engine and then get a gearbox that comes up in the same place.
Just to make it hard, the W50 and W55 have about 3 flavours each, each one identical except for gear stick position.
Also beware that you need the bellhousing that matches an R series engine.
A W50 from an early Cressida is the same as the W50 from an early Celica but they have different bellhousings.
The real trouble will be sourcing a clutch pedal and clutch master cylinder and in modifying the centre console to accept the manual gearstick instead of the T bar.
Don't forget to bypass the neutral/park switch - otherwise you won't be able to start the engine.
- Stepho