Manley Pistons designs and manufactures superior quality racing pistons. With over 75 years of experience in racing piston design and manufacturing between their founders, they are bringing pistons technology to a new level. Manufactured to JLP specifications. THESE PISTONS ARE 20 OVER WITH HEAVY DUTY WRIST PINS IF YOU WANT STANDARD BORE PLEASE SPECIFY . THE PRICE_ IS THE SAME 30 OVER COST IS 50.00 MORE