My A&P just declared my tach junk. I've got a steam gauge 172S. Looks like the a direct replacement SLI model is about $800 plus another $120 or so if I want to set the tach number to match the old one. I've been toying with the idea of putting in an EIS of some sort for a while. The GI 275 wasn't an option until recently, but its features and price jump it to the head of the line. Anyone have experience with this yet? I know the GI 275 is about $4,000. The engine kit is about $1000. The temp probe, should I want it, is around $500. I have no idea what labor would run...anyone know around how many hours an install should take? I have CiES fuel senders already on this aircraft. I have a pair of G5's, but no temperature probe for them. Can the temp probe be shared? They seem to be different part numbers. Having a forest of temp probes on the aircraft seems silly. Even if I need different adapters, can the probe itself be shared? EDIT: Guess another option is the EI R-1. $450, with no fee to set the tach time. But it's a 2" gauge, not a 3", which is a little annoying. Anyone have experience with this one?