Okay
I have compared TT142 (with 3TGTEU), RA63 (with 18RGEU) and TA63 (with 3TGTEU). The Corona (TT142) and Carina (TA63) were identical, the only difference with the Celica (RA63) was the engine mounts, everything else (steering, struts etc) was identical.
Conversion should be the same as for an RA, just make new mounts for the motor to suit.