Sell the Eddy 600, it is too large for a 283. Although a 600 maybe set up for a 350, depending on the output of the 350, it may be too much for that too. If you want to stay with Edelbrock, get a 500, which again may be a bit large for the 283 but it will be a better fit than the 600. I have a 600 on my 350/350 and it works very well, no reason to spend more money for a Holley until the one I got goes bad or begins to irratate me.