There are essentially 3 ways of by passing fuel for the main jet in most all mechanical injected engines – One of these 3 Valves will be mounted between the pump and the metering (Barrel) valve –
The Enderle is a simple 2 lb check valve with a 7003A pill holder and uses screw in Enderle pills
The Kinsler is a snap apart Quick Change valve which uses Hilborn Drop in pills
The Hilborn is the traditional Screw apart Hilborn main by pass which uses drop in Hilborn pills, of course.
Choose a valve below and then order either Hilborn Pills F565 or Enderle pills EN7009