Original sentence: 52% of 1963 LeMans' were equipped with one of the two V-8 engine options.In 1963, the LeMans became a separate series, reaching nearly 50% of total Tempest/LeMans production.In its first iteration, the Tempest was a compact car with an innovative enclosed, curved driveshaft and a rear-mounted Corvair-derived transaxle - a combined differential and transmission that enabled an ideal weight distribution of 50/50.New for 1962 was the LeMans option, primarily a trim package which featured front bucket seats.Performance was strong enough that Car Life magazine stated; "No one will wonder why they didn't use the 389," and fuel economy with the 326 V8 ranged up to 19 mpg.The 155 hp aluminum V8 was joined in 1963 by the Pontiac's 326 in³ (5.3 L) V8, which produced a 260 hp (197 kW) and 352 ft-lbs of torque.The innovative aluminum Buick-built 215 in³ V8 was optional through 1963.This cast iron engine brought weight up a mere 260 lbs over a 194.5 in³ Tempest and weight distribution changed only marginally to 54/46.This engine produced 110 hp (82 kW) (SAE gross) in manual transmission cars or 120 hp in automatic-equipped cars
Edited sentence: In its first iteration, the Tempest was a compact car with an innovative curved driveshaft and a rear-mounted Corvair-derived transaxle - a combined differential and transmission that made the weight distribution between front and rear more even.Road & Track called it "a spooky combination of too much power, marginal steering, inadequate handling, and poor brakes.The aluminum V8 was replaced in the new proto-muscle car Tempest Le Mans by Pontiac's 326 in³ (5.3 L) V8, which produced a respectable 264 hp (197 kW).This early Tempest was soon also available with the innovative aluminum Buick-built 215 in³ V8, which was discarded in 1963.This engine produced 110 hp (82 kW) (gross), barely enough to push the 3000 lb car.This heavy cast iron engine brought weight up to 3400 lb and was not accompanied by much chassis tuning