The GRT EIS is a pretty verstile box and can accept most sensors with a little work using the aux inputs. GRT has hard programmed the oil pressure, oil temp and OAT to use the supplied sensors (VDO for oil temp, VDO or Honeywell for oil press and their OAT sensor). So it's easiest to use them. All other sensors (fuel press, amps, man press etc) are aux inputs and any sensor can be programmed to work. I use Honeywell Hall Effect amp sensors, a UMA differential fuel press sensor, Freescale differential pressure sensors for fuel qty and a Sentra pressure sensor for oxy qty. I wrote a tech note on how to calculate the Scale Factor and Offset for any sensor and it's in the files section of the Yahoo Group for GRT.
The sensors GRT sells are ones that they have tested and calculated the SF and Off for. They all are for aux inputs.
CHT & EGT are thermocouples and are interchanageble - what you have will work with the EIS.
Jim Butcher
Europa XS Rotax 914