Never used!Old Stock-but has been left without a box on a shelf in a workshop for many,many years, which is why there is rust on the intake funnels and some nuts.(The spiders have,of course,been removed).Due to age,all gaskets should be expected to need to be replaced.58DCO3 was used on cars such as Lotus 18 with Country Climax engines,Abarth 2000 SP,McLaren Can Am and properly also other racing cars.