Just replaced 302 with a new 302. Symptoms: runs rough when accelerating, idles fine though, loss of power, Exhaust manifold gets red hot. What I've tried to fix it: Adjusted timing even took it to a shop to ensure it was right, removed cats, sprayed carb cleaner around intake while running...

I did forget to mention that I replaced the stock air intake system with a K&N Cold air intake. It was easy to install, gave the engine a very nice sound, boosted my power just a bit, and improved my gas mileage. I keep a regular check on my mileage for my taxes and I was averaging about 13mpg...