We could never get them right; they were running rich and had a notorious stumble with the .009 distributor the car had. I know some people are happy with them but not in our case. A friend of mine also had a pair and sent them to AJ Sims at Lowbugget to get them dialed in and gave up on them too. After I installed my Dellorto 40’s and saw how nice they work he bought two sets; one for his Speedster and another for his 914 and had perfect results as well. This is in our experience.