Are you sure about the engine being a 198 leaning tower of power??? The converter catalog I have lists only an 11" converter for the 225 engine, but no mention of a 198" engine. It is listed for 225 engines 1968 and up.
I don't know what guy said . I mean my 71 has 198 . They are the same though. Can't even tell from casting number all 198 still have 225 casting apparently. Maybe it was swapped with donor Motor at some point o don't know .