I did some research and found the following info on an S10 forum. Please note that I am freely admitting to steal..err...borrowing this from another forum:

I. Introduction

The S-10 comes from the factory with an independent front suspension (IFS)
manufactured by American Axle Manufacturing. No years of production ever
offered a solid axle, although we all wish they did! This configuration is
prone to accelerated wear and breakage when used off-highway. CV axles,
ball joints, and idler arms are the most frequently replaced components.
The rear suspension is a leaf sprung solid axle, with the axle residing on
top of the springs. The GM 10-Bolt in the S-10's comes with either a 7.5"
ring gear and 26 spline axle shafts, or a 7.625" ring gear and 28 spline
axle shafts. This axle is comparable to the Dana 35 / 35c and 8.25
Chrysler Corporate unit.

II. Preliminary Planning

When you decide to start cranking the SFA gears, there are a few things
that you need to decide before you start. The first is the obvious "Leaves
vs. Coils" debate. While coils will yield lots of articulation, keep in
mind that coil suspensions are much more complicated than leaf springs and
have more axle-to-frame linkages. Also keep in mind the sometimes common
"death-wobble" associated with coil sprung Jeep Cherokees, or
"torque-steer" in Jeep TJ's. After you decide the type of suspension, now
the gears shift into how much lift you want. Leaf springers need to ask if
they want spring over or under, flat springs or arched springs, etc etc.
Coil springers will need to figure out how long control arms need to be
and what coils to use (progressive rate or standard). Each decision you
make at this stage can put you anywhere on the map, so give these serious
thought.

III. Searching for Parts

This is another stage where good planning comes into play. Be honest when
assessing your needs at this stage, as it will save you from headache
later and keep some of your wallet intact. When searching for a front
axle, you want to find something with the differential on the left-hand
side, otherwise your transfer case wont match up (assuming you have the
stock NP 231.) Try to get the tie-rod and draglink with it as well.
A. Front Axles

If you use a Reverse Cut Dana 30 from an '87 - '95 Jeep Wrangler,
it makes life a lot easier. For instance, the pinion yoke and transfer
case yokes are the same, brake lines adapt without hitch, and best of all,
steering is a direct bolt on. Any Jeep Wrangler pitman arm will bolt on to
the S-10's Saginaw steering box. Spring perches are also at a perfect
distance apart, at 31". This allows the springs to sit inside of the frame
rails just as the stage west kit was designed, while spring perches do not
require modification. This unit is very adaptable, and can survive 35"
tires without a hitch.
The Dana 44 is also a great choice for an axle. Almost all of the
parts are available at Pep Boys, Auto Zone, Advance Auto, etc. These axles
can be built from mild to wild or anything in between. Best picks to swap
into an S-10 would be from '66 - '77 Ford Broncos and late '70s and early
'80's Wagoneers.
Note that when swapping the Wagoneer axle, it has a 6-lug pattern that
must be either converted to match the rear, or the rear must have the same
lug pattern. Bronco axles will have the 5 on 5.5" lug pattern, making
adaptation quite easy to other axles. Some came with the Spicer 1310
series pinion yoke, while others may have had the Spicer 1330.
The Dana 60 is the obvious choice for ultimate strength. Used in
many applications over the years, unfortunately none came in an
appropriate width for the S-10. If you did want to go full width, take
into consideration that your tires will not be under any part of the
vehicle. This is illegal in some states, so make sure you know the details
before making a purchase. The Dana 60 is an 8-lug axle that came on just
about any 1-ton pickup. Ford Dana 60's have the driver's side drop
required by the S-10. Like the Dana 44, many axle-shaft, u-joint and ring
and pinion upgrades are available.
Any axle listed here would be a good choice, yet if cost is a
limiting factor, the Dana 30 alone is a great axle. Of course the hardcore
guys will tell ya it is a weak piece; it really is appropriate to the size
and weight of the S-10. So unless you are into some hardcore rock
crawling, the Dana 30 or 44 will prove to be a great bang for the buck.

B. Rear Axles
GM 10-Bolt, Dana 35 / 35C, and some Chrysler Corporate axles all
share the same relative strength. They are considered "safe" up to 33"
tires, but after that, look out. Axle shafts will snap, axle tubes will
spin, and wheel bearings will be eaten up. They are adequate for one who
goes off-roading on occasion, or those with medium to mild trail tastes.
GM 12 Bolts Ford 9"s, and Dana 44's are and awesome compromise
between strength and expense of parts and ground clearance. Availability
of parts its great, where you can get bearings seals, etc at almost any
parts store, and gear/locker choices are innumerable while still not
totally breaking the bank. Ford 9" and Dana 44's are available in
appropriate widths, coming from '66 - '77 Broncos, or late model
International Harvester Scouts. The 12-Bolt was most common in trucks, so
finding one in the right width may be tricky.
GM 14-Bolts, Dana 60's, 70's, 80's, and Rockwell 2.5's are all you
need to know for ultimate strength. These axles were used in 1-ton
pickups, Ford F-250's and up, M1009's and M715's and other military
vehicles came with these axles. 14-Bolts are the most common wrecking yard
find, with prices ranging from 75 to 200 dollars. Military 14-Bolts came
stock with Detroit Lockers and more acceptable gear ratios. Dana 60's are
another common find, but hope that no one has taken out the good stuff. A
Dana 60 in good condition should run about 200-300 dollars. 70's, 80's and
Rockwells come in UPS trucks, Step Vans, U haul trucks, F-450's, 550's,
650's and 750's.

C. Springs
Many people have used all kinds of springs for their projects. The
most popular choices are springs from Wranglers, CJ's, full-size vans,
Dodge Dakotas, and S-10's. In my own project, I used Dakota springs, with
a CJ add-a-leaf. In the near future, I plan on adding another main leaf
from some Dodge Dakota springs.

D. Steel / Misc.
When fabricating my mounts for springs, I used 3/16ths Box tubing
for my cross member and other brackets. You can use 1/4", but in my
opinion, i would rather save weight and use the 3/16ths. It is strong
enough to carry the weight of the vehicle, while not burdening the rest of
the vehicle with excess weight.
When designing a leaf spring suspension for an S-10, the trend is
to make a cross member with a drop to it that is welded to the bottom of
the frame in the front. The Stage West kit is designed like this as are
the vehicles owned by Randy Danielson, Paul (Blackhawk on
www.s10-4x4.com), James Loar (jrloar on www.s10-4x4.com), and myself,
Darrell Krueger (fullreversal on www.s10-4x4.org.) Especially important in
the front, to prevent unnecessary negative arch to the springs, is to have
the straight line connecting the endpoints of the spring to be almost if
not exactly parallel to the ground plane. If you look at the Stage West
kit, the drop bracket and where the end of the shackle is is a parallel
line.

IV. Pre-Swap Fabrication
Before you swap, it is important to know that you can weld on
cross members and test fit springs before chopping any bit of IFS off.
Also, be sure to drill a 3/4 " dia. Hole through the frame exactly 3
inches back from the original hole that Stage West used for mounting the
shackle bolts. Be sure to sleeve this hole with some .75" tubing. If you
plan on doing a Stage West style swap, note that Dakota springs are the
closest match to the springs that they supply with the now-discontinued
kit. When fabricating your cross member, assuming that you have leaf
springs, make sure that you are absolutely sure of your welding skills. If
not, have someone else do it. Remember, the weight of your front end will
be on these springs, so you don't want any shoddy welds breaking in the
heat-of-the-moment.

V. IFS Removal
This can be taken care of with an acetylene torch, plasma cutter,
or in its simplest form, unbolting as much as you can, then using a 4.5"
angle grinder and a cutoff wheel to eliminate any offending IFS brackets.
Retain the shock mounts as they can be used with relative ease on the new
axle. Take extra care not to knick the brake lines (rubber or steel) and
make sure to disconnect every connection to the center section before
letting it drop. This includes breather hoses, electrical connections, CAD
cables, drive shaft, etc. This is the most time consuming process in the
whole swap, taking up 1- 3 "average persons" days. My swap took about a
week and a half working at a leisurely pace after work in the weekday, and
all day on Saturdays and Sundays.

VI. Assembly (Front)

By this time I am assuming that you have checked and
double-checked you measurements of your cross member and shackle
boltholes. In my situation, I had a cart that you move furniture with.
It's about 3 inches off the ground, has some heavy-duty casters on it, and
has a wooden deck on it. I bolted the springs to the axle, along with all
of the steering components, and placed it on the cart. From there, I just
wheeled it under the vehicle and bolted the front of the springs on first
(the end that doesn't have the shackle.) Next, attach the steering,
brakes, and electrical connections (4wd light switch). Do the drive shafts
last, since this requires the skills of a driveline shop.

VII. Assembly (Rear)

The rear is fairly straightforward and doesn't require that much
thought. Basically, it involves removing the old axle, retaining the old
hard brake lines, and preparing the drive shaft for adapting with Neapco
PN 3-3130. After removal of the axle, attach the springs to the shackles,
wheel the new axle under and set the spring pads onto the axle. Now set
the pinion angle, making sure that the angles at the transfer case and at
the pinion cancel each other out. This will eliminate any driveline
vibrations. In my case with a simple spring over in the rear, I didn't
need a new drive shaft. It's a little short, but it still has enough room
to do its job. When welding spring perches, make sure you only do about 1"
at a time on opposite corners of the spring perch. This will reduce
warping created by the welding process. Be sure not to test-drive the
vehicle with just tack welds on the spring perches. I made that mistake
and caught myself just before I drove off. As soon as I put it in drive,
the initial lurch of the vehicle snapped the welds and sent the pinion
vertical, almost destroying the U-joint and pulling the drive shaft out of
the transfer case. Emergency brakes aren't tough, but do require probably
the most effort, due to adapting cables and getting them to hold just
right. In my project, I took out the E-brake stuff, and will install a
line lock soon.

VIII. Test Drive Preparation

Before getting all antsy and wanting to drive it around the block
or over your neighbors landscape, make sure that you will be safe when you
ride in it. Here is a checklist:
Are the tires inflated to recommended pressure?
Are the brakes bled thoroughly?
Do the tires have adequate clearance?
Does the steering move freely?
Is the drive shaft secured to the transfer case and axle securely?
Are all suspension bolts / nuts and lug nuts properly torqued?
Are the axles filled with the appropriate amount of gear oil?
Have the wheel bearings been packed with grease?
This is just a basic checklist, and there are probably more things to look
over. Remember, it is the owner/operator's responsibility to make sure
that the vehicle is safe to drive.

IX. Test Drive

On the initial test drive, I recommend taking the vehicle for a
short test drive in your neighborhood, away from heavy traffic, and not to
stray too far incase you need to be towed back home. Take careful note of
the handling characteristics, braking distances, whether or not you have
bad axle wrap under acceleration, etc, etc. Fix each problem, and then
take it out for another test drive. By doing this, you will keep
uncovering problems until you are ready to take it off road. Remember that
when you have a lifted truck, your center of gravity will be raised, your
braking distance will be increased, requiring a more alert driver. Be sure
to adjust your driving style accordingly.

X. Final Thoughts

This project is easy to do unless you psyche yourself into it
being a difficult one. Here are three pieces of advice I would like to
pass on. First get damn good at welding, or shell out to have it done for
you. Second, don't be afraid of the project. There are many who have done
this conversion and can offer help if you really f-up. Finally, do not
start this project until you have absolutely every piece that you will
need. Do your homework, and plan well. It pays off. I spent a whole year
planning, and when it came time to do everything, I ran into fewer snags
than most people, and completed the project in less overall time. Don't
get yourself down about "not having the fabrication skills needed." Anyone
with half of a brain and who likes to do some work on their car/truck will
be able to do this project. Good luck!