Outer Limits 4x4 Board

Hi all I own a 2003 patrol 3l manual with 35in tyres but thinking going 37 in the future. My question is what % reduction would suit ive read that most people go with the 85% but was wondering if there is a 50%or near enough also how difficult are they to fit im mechenical minded and have been doing stuff of patrols for years but never the gears
any info will be great
cheers pete

marks adaptors do 28%?, 43% and 85%. google gearmaster.

Have a read of this thread.

http://www.outerlimits4x4.com/viewtopic.php?t=67207

go the most reduction you can get, if its too low put it in 2nd, 83% aint 83% if you change tyre sizes