Outer Limits 4x4 Board

looking at buying a bj40, ive got a couple of h55f gearboxs lying around from old 60s and was wondering if they fit at all at the bell housing end and the chassis mounts. I realise i will probably need new tail shafts as the lengths will be different.

also do you think this is worth the effort for the added economy?

whats the mileage like on a bj?

input shaft on a b series is different to all 6 cylinder diesel or petrol. bell aswell (to suit) so u need to swap them into the 55 if that is possible, or get the right part, as the later 42's came h55 i see no problems.