Simple bolt-on modifications, and proven...I've seen plenty of the small Holley 4-bbls, as well as the multiple 1-bbl setups on all sizes of 6's. With headers and a cam, they're HOT. Without the cam, the improvement is marginal, and some tuning may be required. But, I've never talked to anyone who didn't like it! Remember, a performance improvement generally involves an efficiency improvement...just keep your foot out of it!
