440 running bad. Popped the valve covers off and my friend was able to compress several of the springs by hand. Said that was bad. He says the springs "forgot where they were supposed to be" after sitting in a semi compressed state for over 12 years. Any ways, I figured I might as well upgrade. I have the Purple cam, 750 DP Holley on a torquer intake, 1 3/4 headers and a standard bore and pistons. The heads are stock 346 heads. This is just a 4 speed street car. I want to replace and/or upgrade the heads and valve train to maybe get a few more hp. I'd like to limit cost to around a thousand, but I don't want to go too overboard. You know the law of diminishing returns. I have basically zero engine knowledge so would appriciate any advice.