• The Buick 455 lifter valley can be modified to improve horsepower.Classic sports car interior image by itsallgood from Fotolia.com
  
  Muscle cars are small cars with big engines. The Buick 455 is one such muscle car built between 1970 and 1974. Between 1970 and 1971, the Buick 455 was adapted in accordance with stricter government emissions and fuel use regulations. Several changes were made in the valve lifters and camshafts. These differences caused an increase in friction and drag, reducing overall engine performance and horsepower.
  
  

Lifter Differences

• In 1971 the Buick 455 compression ratio was reduced from 10:1 to 8.5:1. In 1971, engine horsepower also declined, from 350 to 315. This was due to the use of flat-tappet camshafts with valve lifters that produce excessive drag and friction in the camshaft. The Buick 455 flat-tappet camshafts can be replaced with high-performance roller camshafts and roller valve lifters to increase engine horsepower and reduce fuel waste.
  
  

Lifter Modifications

• Improving the lifter valley of the 1971 Buick 455 will reduce the effects of the performance decline due to the emissions and fuel use regulations instituted in 1971. There are two main ways to improve the performance of the lifter valley: by strengthening the lifter bores and re-sealing the lifter valley. These changes will reduce oil aeration and lead to an increase in engine performance.
  
  

Engine Specifications

• The 1971 Buick 455 has a wheelbase of 112 inches and weighs in at 3,461 lbs. The 1971 Buick 455 has a V-8 engine with a displacement of 455 cubic inches and produces 315 horsepower at 4,400 RPM. The Buick 455 generates 450 ft.-lbs. of torque at 2,800 RPM and accelerates from 0 to 60 miles per hour in 6.9 seconds.