The LT230 is a t-case, so has no mainshaft. It only has an input, intermediate and output shafts.

In a gearbox the input shaft is on the same axis as the mainshaft.

So:

R380 - "Rover", 380 Nm rating, 77 mm between the input/main and intermediate shaft centres
LT77S - "Leyland Transmissions", 77 mm between the centres, Strengthened
LT77 - "Leyland Transmissions", 77 mm between the centres
LT85 - as above but 85 mm between centres
LT95 - as above but 95 mm between centres

LT230 - as above but 230 mm between Input and Output shaft centres.