Join Inliners International, -- first.
Second -- buy Leo Santucci book on 6 cyl motors.

Buffalo Steve advertises (NO web site) in Inliners International, can make you the motor mounts or try Saches catalog for donut style motor mounts. w/ Buffalo's mounts he gives you three ways to mount/weld the mounts in case later on you wish to add a later style steering box or possible IFS.
You're going to have to change the rear end so check mid 70's rear end 10 and 12 bolt, threr are many other rear ends available.......
http://www.50chevy.freeservers.com/Suspension_Widths.html ...... to calculate rear end ratios try this site:
http://www.smokemup.com/auto_math/mph_range2.php
Some rear end guys can build you a rear end and have all the hangers removed, then when the new rear end gets set up in your truck the installer can weld the new hangers at a 3-4 degree angle for the driveshaft. Be careful about welding the hangers and tweeking the axle. Find a junk yard for the T5 front yoke u-joynt for the drive line.
You may have to consider changing brake master cylinders because of the new rear end, as your stock is too small.

You might be able to find a large tranny shop and have them build you a T5 using camaro guts installed into an S-10 housing as a complete unit, i got mine done in Sacramento.
or
The more common is junk yard camaro /firebird T5's and an S-10 rear cone housing to move the shift point forward.

good luck cause it's a lot of work, have fun
gooday


Gooday
Jim

small wheel moves by fire and rod,
big wheel fires by the grace of god,
everytime that wheel turns round,
bound to cover just a little more ground.