318 LA torque?

I have a 318 1983 ALL stock in my 1983 d150 it runs great for how old it is and I'm wanting to make a low end torque house engine build out of it on a rough under $2,000 budget. I'm wanting to get new cam, and possibly valve train, I don't want to go too big on heads, I was thinking the 302 swirl ports if I got new ones but i plan on doing port job on stock heads if not. I'm looking for around 300 to 350 torque to the wheels at around 3,000 rpm if that's possible for it. What should I put on it to get what I'm going for?