I have a stock 289 with tri-y headers, a one inch spacer on the stock intake manifold, and a holley 600. I'm pretty sure the heads are stock. the car is also a four speed with 2.80 rear gears. My question is, with keeping the stock heads what is the best cam I can get for the most horsepower and torque? This is not necessarily a daily driver but driven often in the summer. A rough idle would be nice but not to the point that it stalls out at every light. I would love to build it up to 375 hp, but that isn't going to happen with stock heads and intake. So how much horsepower do you think I might be looking at by just switching out the cam? Thank you for your replies. 
