http://www.zcarparts.com motorsports website, they have a few headers and full exhaust systems at prices that are hard to beat, they also have the cams, as for additional power if you rebuild, flat top pistons, the 280 came with dish pistons offering an anemic 8.29:1 comp ratio, flat tops will get you up to 9.82:1 also head gaskets in varying thickness will adjust comp ratio a bit more, ,any over bore will up the comp ratio, and of course there is the intake MAF conversion or carbs, oversized injectors, increased fuel pressure, you could do a stroker or a turbo, just depends on what direction you want to take with it