 For 1973, FIAT executives imposed a new technical staff and Forghieri was transferred to the "experimental department"; his role was taken by Sandro Colombo, a former Gilera and Innocenti engineer.The "spazzaneve" project was discarded and replaced by a new design, still named 312 B3.A new full monocoque chassis was built by specialist English company TC Prototypes, under John Thompson's guidance, and the engine became a fully stressed member.