which technique is better and why?
i have an 01 raptor and wanted better dune hill climbing speed.which way is best?

 

You lose less power by going higher in the rear. It robs some power with a smaller front sprocket due to the tighter radius. Just make sure your skidplate will handle a 43 tooth or you will have to shim it. In the trails though, it isn't much of an option to leave the front at a 13 tooth since 12/42 seems to be the right combination. This would be the equivalent of 13/45. You would lose a lot of ground clearance with the combination plus need a longer chain.

/NotuRaptor