99 s10. swapping original 4.3 for 305. help!!!?

i have a 99 s10 (stick). the original 4.3 is shot. and i finally have an excuse to swap the motor. i want to drop in a 305 small block. will the tranny and rear end work with the bigger engine? also, any MAJOR alterations that would have to be done under the hood would be extremely helpful. thanks.

The only thing I can remotely see you having a problem with might be the bellhousing m ounting to the block. I am unfamiliar with the newer 4.3's however and havent a clue about the newer gen small blocks, so it very well may work with no problems.