Originally Posted by RicksAlfas
People tend to use the 8 valve Twin Spark out of the 75, as it has come out of a rear wheel drive configuration, and is all alloy... the Fiat based one is an iron block.
The 8valve unit in the 164 is an all alloy unit, developed from the previous Alfa engines unlike the Q4 which was the Lancia unit and the 16valve that used the fiat bottom end. Hence there are limited variator problems as it shares this with the 75, unlike the later engines. It was altered slightly in 1992 when the capacity went from 1962cc (same size as the 105 car 2l) to 1995cc acompanying a new crankshaft, re-profile head and cams due to the fitting of the CAT. The earlier engine has the 2 distrubutors at either end of the head like the 75 too. Will need a new sump cover too, Maxbanks is probably the best person to advise though.
Nick