Yea, there is a conversion kit built that will drop a 350 chev or a 302 ford motor into your yota. The 302 is a tad easier due to the distributor being on the front. The kit comes complete with bell housing, clutch, and detailed intstructions. You can also go for a 3.8 V-6 that works too. Yes your tranny will handle it unless you start hammering the truck on the road or slickrock. It can't handle 200 HP burnout.
Here is an awesome detailed swap article:
http://trucks.about.com/gi/dynamic/o...%2Fv6swap.html
good luck!