2406-4030 383 Small Block Chevy FX Series -28cc Dish Top SBC 23 Degree Forged Piston Set 4.030 inch bore Pin Dia.: 0.927" Comp Height: 1.125" Bore Size 3915 in 99363 mm Because the singles you are

Because the singles you are purchasing were not made at the same time your original pistons were made there will be variations that could effect their weight

best engine building practices dictate that pistons should be replaced in matched sets

If it does it requires a

That being said

2406-4030 383 Small Block Chevy FX Series -28cc Dish Top SBC 23 Degree Forged Piston Set 4.030 inch bore Pin Dia.: 0.927" Comp Height: 1.125" Bore Size 3915 in 99363 mm Because the singles you are383 Small Block Chevy, FX, Comp Height: 1. 125, 28cc Dish Top, PIN: . 927", Full Floating or Press Fit, Ring Groove: 1. 2 1. 2 3MM, Stroke: 3. 750", ROD: 6, Approx Comp Ratio: 58cc 9. 31, 64cc 8. 82, 70cc 8. 38 *