Outer Limits 4x4 Board

have been trying to find info on flipping the standard rear springs on a 77 fj40. looks like if i fit larger tyres they'l rub on the front of the wheel well when flexing. from what i have gathered, i can flip the springs under the following conditions:

1. shock mounts move to behind the cross-bar by grinding the welds and flipping the through-bolts.
2. the diff pinion will point down. this is a weaker configuration, though i imagine the risk of breaking is reduced as it is not lifted.
3. i will need a spacer at one end of the prop shaft to make up the new distance.

if this is all correct, can anyone comment on whether or not this job is worth doing? any experiences appreciated.

To flip the springs youll need to get the drive shaft retubed, or shorten one from a 60 or 70. Spacers wont get you enough. You will need a new rear brake flex hose. You gain about 3.5 inch wheelbase.
In stock configuration, the axle is located by the stronger shorter side of the spring pack, but many many people have flipped packs and no problems.
Youll need to cut sheet metal to get the wheel centred in the arch when the axle is moved back.

When I fitted my 33s and 35s, I just redrilled the spring perch on the axle and moved it back 1.5 inch.. This was plenty to clear the tyres on suspension compression.. I have the stock brake line and drive shaft.. There is enough engagement on the slip joint for it to not be a problem, but I'll eventually install a spacer to prevent premature slip joint wear.

Another option is to install 55 rear springs.. These are longer and have a centred pin. Adjustments to the shackle length or hanger position need to be made to make these work..

you will notice a hell of alot more axle wrap.

a better modification is to fit up longer rear springs (i.e. fj55 rear springs), or use springs that have a centred spring pin (i.e. fj55 or Hj75 front springs)

thanks guys, redrilling sounds pretty good for my needs. vk7ybi was there any issue with the shock mounts?

The rubber bushings are deformed a bit, but thats about all.