Chevrolet Repair: motor, chev, 3l

Question
what size motor can i put in a 1995 chev s10 4 or 6 ? it has a 4 in it now

Answer
are you asking because you motor is bad?? or because you want to upgrade??

If you are just trying to get the truck back on the road, go with the same for ease.  If you want to upgrade, a Vortec 4.3L V-6 is the normal motor for this truck.  Some people put in 350 V-8.

Remember that other than the orginal motor, you open the door to numerous complications.