After strong demands from the aforementioned privateers the Scuderia set out to create a racing version of the 512. Pininfarina was commissioned to create a very streamlined silhouette body, to allow for high speeds at Le Mans' long straights. Ferrari themselves put the chassis on a diet, taking the weight down with around 200 lbs. Unfortunatley the huge new body added about the same, so in all no weight was saved. The flat 12 engines were fitted with Lucas Fuel Injection and power was increased to 460-480 bhp. At the end of its career power was up to 500 bhp.
Porsche and the 512 BB's gearbox prevented the 512 BB LM from ever becoming a success. Problems with the gearbox were two-fold. To reduce the wheelbase, Ferrari mounted the 12 cylinder engine on top of the gearbox, but with so much weight high up in the car handling was severely hampered. The second problem was its reliability; Ferrari increased the engine output by over 100bhp, but did not modify the gearbox to cope with the added power.
Ferrari's Series II BB LM's were constructed over the winter of 1978 so as to be ready for 1979's season opener, the Daytona 24 Hours. This second batch of LM's were to feature many important developments over the almost standard-by-comparison Series I's. Taking advantage of newly revised regulations, length was increased by 16-inches, entirely new bodywork being designed while the chassis was heavily modified to reduce weight and increase rigidity. It seemed Ferrari were finally getting serious about the Boxer competition programme.
Output was increased to 480bhp, the Weber carburettors of Series I LM's being replaced with Lucas fuel injection. There were lightweight polished conrods, high lift camshafts, a free flow competition exhaust and increased compression, exotic manufacturing techniques being used throughout. Pininfarina crafted the all-new bodywork and spent a great deal of time perfecting it in the wind tunnel, the final design bearing almost no resemblance to Ferrari's production version other than around the cockpit. The Series II was markedly longer than Ferrari's stock model and a good deal wider, its stretched nose featuring a reprofiled valance that housed headlights under clear Plexiglas. Gone were the retractable items and distinctive supplementary light covers that gave the road car its unique identity. Pininfarina stretched the tail as far as the regulations would permit, the massive rear overhang providing obvious handling and stability benefits at high-speed tracks like Le Mans and Daytona. The tail facia was dominated by an aluminium rear wing and huge meshed grille that allowed hot air to escape from the engine bay. With lightweight panels and a stripped-out interior, weight was reduced to around 1150kg. Ferrari's final batch of 512 BB LM's featured far fewer developments than had been the case between Series I and II cars. Other than subtly reworked 500bhp engines, there were a few visual tweaks, Series III's all getting ventilated side skirts to improve airflow. Manufactured with even lighter components than previous versions (some weighed in at as little as 1058kg), the Series III was the fastest BB LM of all. Sixteen were made between early 1980 and late 1982.