IF IM GOING TO RUN  37" OR 39.5" TIRES WITH THE SAMURAI 1.3 HOW LOW SHOULD I GO? UNTIL I FIND A 1.6 8 VALVE AND THEN WHAT GEARS SHOULD I RUN WITH THE 1.6?

THANKS
ROBBIE

Your going to have to give alot more info to answer that one! off road only, volvo 404's, dana 60's?

dana 44's and yes offroad only

IMO, 5.89, and 4.x in the tcase.

You can run anywhere from 3.92-5.89 in the Dana 44.  It really depends on what transfer case you are running and if you want lower then stock or just straight stock gearing.

If you want equal to stock gearing, just calculate your tire size difference and use that to multiply your gearing in your axles.

New Tire/Stock Tire = Difference in size.  Difference in size * Stock Gearing = New Ratio Required.

The stock tire is 26.5" and the stock gearing is 3.89, so 'New Tire / 26.5 * 3.727' or roughly 'New Tires/7.15'.

37" Tire = 5.2 gear ratio.
39.5" Tire = 5.52 gear ratio.

However, you can just get lower transfer case gears to make up some of the difference.  If you have a 4:1 kit with a 10% high range reduction you can change your calculations a bit by adding '*.90' onto the end of the equation.

37 (New Tire Size) / 26.5 (Original tire Size) * 3.72 (Original Gear Ratio) * 0.90 (Gear Reduction in Transfer Case)

If you want to get really fancy you can put the true gear ratios at the end in the Gear Reduction spot as (1.409/New High Ratio).

Additionally, you can use this utility I found while double checking gearing numbers to just type in your ratios and see what the change in overall ratio is. 

http://www.lepayne.com/gears.html

Yea... I was bored this morning.   

wow thanks that gives me somewhere to start also to finish haha.

thanks again

Robbie