i have an 87 samurai with a 6.5 t-case stock axle gears i found some 5.12 gears out of track/kick fronts
will the fit my axles and is that to much gears for driving every day?

1. Yes the fronts will.  The best way to install them is to swap the ring and pinions  It's a stronger reliable swap compared to using the aluminum housings and weaker spider gear assembly.

http://www.zukikrawlers.com/showthread.php?t=4215
http://www.acksfaq.com/difcans.htm

The above links were found using a search for ring and pinion at ack's FAQ (see link in signature).

2.  Probably not.  According to the Samurai gear calculator at acks FAQ, 6.5 tcase (high ratio, i believe, is 1.691) + 5.12 R&P + 33" tires in fifth gear (pre-'88) and 3800 RPM would result in a speed of 54 MPH.  At 4000 you would get 57 MPH.  I assumed 33" tires but you can go to the calculator and plug in your specific tire and engine values.  

BTW, the value below the low range output in the calculator's t-case gear choices is the high range output ratio for the set.  Thus 6.090 and 1.747 would be pairs.

I hope that this helps!

that help a lot   has any one run this combo  i run 33 12.5 swamper ssr's

I forgot something semi-important:

Bigger tires = more weight = less engine performance.

Now, let the guys who have been there and done that comment!

Do you like doing over 60 on a regular basis?  If so I wouldn't use the 5.12's with the 6.5.  I run the same combo on my SJ-410.  It works great for power and running around, but with the 4 speed at 53mph I am turning just over 5K on the tack.  With a 5 speed you should be able to run 60 or so, but that will top it out.  In low range I max out about 14 mph in 4th gear.  With a 5 speed you should easily be able to get up to 17 or so before hitting the red-line.

But if you don't plan on going over 55 when cruising around they will give you plenty of power.  I only have the 970cc and am pushing 45hp instead of the 65 of the stock Samurai but can motor around without issue with 33x12.5 Pro-Comp ExMTRs.  Just not enough RPM's left at the top end for road use.

I also recommend installing a traction bar if you haven't already.  That will give you a bit more power for driving around as your springs will not be able to soak it up.  Kahn Sultan recently wrote a thread with some good shots of the finished product.