Try this on Google, and you'll see a couple
Chevy s10 v8 engine swap
There are really 2 ways to get a V8 powered S10.
1 way is to build it. You can get someone else to do all the work, but you'll need very deep pockets
The second way is to just buy the S10 that already has a V8 with it
The conversion parts can be bought trough Advanced Adapters, or you can just make your own.
A few people on this forum have done the job, and will probably assist you when you need advice