OK, an info tidbit.
Installing a 2RZ, using an A340F from a 22RE currently in my truck, swapped bellhousings from a 2RZ A340F. Have a extra A340H from a 3VZ laying around.
My 22re A340F and a 3VZ A340H trans have the same spline count on the inputs. The Torque converters are interchangable between the 22RE and the 3VZ, but the flex plates aren't because of a diffenent bolt pattern to bolt the converter to the flex plate.
2RZ flexplate will bolt to a 3VZ TC which fit in my 22re A340F trans.
My 2RZ A340F torque converter doesn't fit my 22RE A340F trans. because of spline count of input shafts are different. Coarser spline on the 2RZ A340F input.
A 22re, 2RZ and 3VZ all have different flexplates.
Confusing, kinda, but I tried to describe all the variations.
Glad I had gathered some extra trans and parts, but now we know.
