Friend who has his SBC in an earlier version - it just has a simple plumbing valve (1/4 turn) inside the cab. Works well if that's all you need. I have a couple plastic heater valves and cables hanging out in the garage from other vehicles that someday I will install... but that's about 1,000 on the 'to do' list... Ha - when you have a rig that hasn't seen use in 30 years (and it wasn't well taken care of) going and stopping seem like top priorities.