i currently have a 3.1L v6 mpfi in my 92 RS (but it doesn't start) and i might be getting a 5.7L 350 (carb)out of late 80's chevy truck (it's free so i don't care). What kind of mods do i need to do this and will the motor mounts for either the truck or my current ones work or do i need new ones?

 

It's a V6 to V8 swap, many posts on what's needed (like another going right now). Look through the posts for the last month or so, you'll have all your answers.

If you're disturbed now, you'll be even more so after this job. The best way to do it is to get a factory V8 car for all the parts you need, even if you don't use the engine. Even with the free engine, after you're done you will have spent more doing it than you would if you sold your current car and bought a running factory V8 car. Put your free engine into that.

Unless this particular car has some sentimental value, like being your first car or you dad bought it new, it really isn't worth it. Love mine, just didn't go about getting a V8 3rd gen car in the smartest way.

 

Would the swap be worth it for me? My v6 was cheap, really got it for parts. If I were to do a v8 swap it would be to make it a wild drag car. Do you have to weld motor mounts in or do you just bolt them in? That's my only question.

 

the mounts bolt in. You have to buy v-8 mounts, then move them to the forward most holes.