318 to 360 swap screwed up big please help!!!

Thanks. Yeah, I already swapped oil pans from the 318. One more thing. Just for fun, what do you guys think I'll get for horswpower with my bone yard 360? Being an R.V. Motor, I guessed between 275 and 290 with headers, my good ignition, edelbrock performer rpm manifold, new holley 600, and headers.