How can I make my truck from a v4 to a v8. Would I need to buy a new engine or just fuck it and save up for a new car or truck. I drive a 1998 chevy s10 stick 5-speed.

You will need a new motor, new motor mounts, and a serious amount of modification to the engine compartment to fit a V-8. Also, for a '98 S10, you may also need a new transmission. Someone may correct me if I'm wrong, but I would be surprised if the stock transmission gearing can handle the torque and power from a crate V-8. I would save your money for a truck that's already got a V-8. Ford used to pair 5-speed manual transmissions to their V-8's, you may be able to find one on ebay.

you will have to swap transmission. usually this is done with a th350 trans. this swap is probably well documented on a forum dedicated to s-10's. this is a common swap, having been done since the late 1980's.