i have an exhaust leak in my exhaust manifold because there isn't a gasket there. i've been told it will be really expensive for a mechanic to do it. anything i should know before i do it myself or any advice? anything would be great.

 

Stock exhaust manifolds? It's pretty simple since you don't have to take the whole manifold out. It's not like a header swap. Just take out all the bolts, pull the manifold away from the engine, slide in the gasket, bolt back on. Search header install to get tricks/tips on just taking the bolts out.