ive searched but havn't found a forum with all the different stock axl ratios for a sammi.
and are there markings or year differences in the axls?

my 88 rounds out to 3.73, your 87 is prob. the same, older stuff was around 3.9 and 4.10's the older ya go. smaller stuff also.

i trashed my rear on my 87, and today bought a another axl but did not know the ratio in it.
my old ring and pinion are missing teeth.was going to see if there where any markings to tell what it is.i jacked the sammi up to spin the diff to see what the ratio is ,but every thing spins so easy i can't tell.my front is stock, i think 3.73.

just count the teeth when ya get them out, pinion 10 t ring 41 teeth= 41 divided by 10=4.1 or 4.10's  kinda thing. just make sure the teeth count match.

ive searched but havn't found a forum with all the different stock axl ratios for a sammi.
and are there markings or year differences in the axls?

US Samurais (1987-1995) came with 3.73 difs.

try this link at Zukiworld:

http://www.zukiworld.com/section_technical/technical_spec_samurai.htm

In the middle for the page it states that the SJ-413 (Samurai's "other" name ) changed from 3.727 to 3.909 for the 1996 model year. Unfortunately, US sales ended in 1995...

There are LOTS of ways to get different gear ratios from buying aftermarket gearsets to cannibalizing TracKick FRONT differentials for their R&Ps.

hope this helps!