Don't know about doing it with a TH 400, but I did it with my TKO 600 installed on the engine. You will have to put the front up on jack stands for the tail shaft housing to clear the ground until you can move the whole assembly back. Did this without a load leveler. Didn't know there was such a thing. guess I worked hard not smart Now I highly reccommend a load leveler! It will save you some paint and skin!