Since actual TIII lifters are getting hard to come by, and often have issues when you do find them even new, what's the other options? We have a rebuilder looking at some for a Spirit RT I'm working on, and I found mention of some successfully using a Mercedes V8 exhaust lifter on the other site. My thoughts were that if Lotus designed the head, seems like they'd have used a lifter they or a supplier already had in use, maybe in an Elise or Espirit. How critical is it to have the little foot on the bottom, could a lash cap be used on the valve stem instead?