I think they work very well on a street machine with a four barrel. I am using one currently on my car, built it about eight years ago. Total investment is usually $25.00 or less plus your time. I have never dyno one to compare but if you want to do it yourself and don't wish to pop for an after market unit then have at it. Some guys just enjoy making there own like we did back in the day when the aftermarket arena wasn't as large as it is now. Keep in mind that all those guys you read about that originated the parts you buy today started out making a part because they couldn't or wouldn't go out and buy it. Some even got lucky and became famous others just had a sense of acomplishment that they did it themselves.
