will a 1995 camaro 350 fit a 1991 silverado

if the bolts line up and the linkage is the same I don't see why not...the vacuum anticipator or such...

The block is the same. There are differences in the cam shaft, and a few other things. The truck engine likely has more torque, the Camaro engine has more horsepower. With the swap, you are likely to find the truck slower off the line but faster in the mid-range.

Personally, I would steer away from the swap.. The 95 camaro used the LT1.. That engine is an absolute nightmare when it comes to problems (speaking from personal experiance). But to answer your question, yes it will bolt in. You will need the complete wiring harness from the camaro (including ECM).