Lamborghini Miura manual indicating bigger intake valves in English size (but correct size in metric). The intake and exhaust valves in all 4 liter Lamborghini V12 remained the same throughout all models. This intake size misprint carried forward into Espada 400GT and Countach LP 400/LP 400S owners manuals as well. In 1970, Lamborghini development driver Bob Wallace created a test mule that would conform to the FIA's Appendix J racing regulations. The car was appropriately named the Miura Jota (the pronunciation of the letter 'J' in Spanish). Wallace made extensive modifications to the standard Miura chassis and engine. Weight reductions included replacing
Lamborghini Miura steel chassis components and body panels with the lightweight aluminium alloy Avional and replacing side windows with plastic, with the resulting car weighing approximately 800 pounds less than a production Miura. A front spoiler was added and the headlights were replaced with fixed, faired-in units. Wallace substituted two smaller, sill-mounted fuel tanks for the single larger original unit. The suspension was reworked and widened (9" in the front, 12" in the rear), and lightweight wheels were fitted. The engine was modified to produce 418–440 bhp at 8800 rpm, with an increased compression ratio, altered cams, electronic ignition, dry-sump lubrication and