I know this question has probably come up before but which is best? A little info on the engine....Its got about 4k on it, it has Hypereutectic pistons, Edelbrock Performer cam, intake, heads, and shorty headers, and a chip burned by Edelbrock. Running electric fans, Dual cats w/Flowmaster 40s through 2.5" pipe. Its got a lot of torque down low but seems to be a little off on the high end. I am looking for performance. Fuel economy is cool, but I want performance. Found several Holley 670s on ebay but have heard a few negative things about them. I know I will have to have my intake bored out to match for best performance. Also looking at getting the CFM-Tech kit or a big block TBI. I want something easy to install that I dont have to do too many mods to get to work right. Want a bolt and go thing. I also know I will probably have to have another chip burned but thats no big deal. I will be putting a Carter inline fuel pump in when I get a chance.