I bought some lightly used 3 way adjustable CE's. I put them on the 90/10 setting and leave them there all the time street or strip. They seem to work fine for my level of performance.

As I recall they were a little confusing on the adjustment markings and opposite of what they should have been. work

'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.