here article on modding IAT and ECT sensor inputs .
http://www.autospeed.com.au/cms/A_110350/article.html?popularArticle
you need to be careful your not changing timing and fuel at same times.
Also many vehicles have multiple ECT sensors, generally one for ECU fuel amounts and you could have ones for radiator fan switch on temp and also gauge temps, rarely are same sensor used for all 3 .