RE: 4 shock to 2 shocks
no but you should just take the inner ones out and keep the outer in the same position. you will also have to change the shock oil in the shocks. with an OG mammoth and 4 shocks, try 50wt. It will handle better that way. this is if you race.
Or you could just keep all 8 if you just bash around and it will be fine.