Outer Limits 4x4 Board

Did a search all i can find is info for hiluxes and zooks. basically i want to know is if i run longer front leaves like 100mm, can i run standard length shackles in their standard location??? and if yes would there be that much benifit if any?? im thinking that in doing so it will allow my shackles to sit on more of an angle as now they are bascically straight up and down and dont allow much droop. also what things are there to look out for apart from prop shaft lengths, possibly castor angle to look out for?? any info would be appreciated.

cheers
mick