Free Shipping on Piston Orders Over $500.00! Online Purchases Only. Limited Time Offer. Continental U.S. Only.

Mopar Challenge R/T

Mopar 340

STEP 1: Choose Cyl Bore Size Show all STEP 1: Choose Cyl Bore Size
STEP 2: Piston Series Show all STEP 2: Piston Series
STEP 3: Connecting Rod Length Show all STEP 3: Connecting Rod Length
STEP 4: Piston Pin Diameter Show all STEP 4: Piston Pin Diameter
STEP 6: Top - Comp. Ratio Show all STEP 6: Top - Comp. Ratio
Compression Height Show all Compression Height
Crankshaft Stroke Show all Crankshaft Stroke
6300-4040 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.040 inch bore Pin Dia.: 0.984 6300-4040 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.040 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
339 Small Block Mopar, FX, Comp Height: 1.802, -3cc Flat Top , PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-10.46, 64cc-10.21, 72cc-9.33 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6300-4070 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.070 inch bore Pin Dia.: 0.984 6300-4070 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.070 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
345 Small Block Mopar, FX, Comp Height: 1.802, -3cc Flat Top , PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-10.6, 64cc-10.35, 72cc-9.46 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6300-4080 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.080 inch bore Pin Dia.: 0.984 6300-4080 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.080 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
346 Small Block Mopar, FX, Comp Height: 1.802, -3cc Flat Top , PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-10.63, 64cc-10.38, 72cc-9.48 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6300-4100 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.100 inch bore Pin Dia.: 0.984 6300-4100 340 Small Block Mopar FX Series -3cc Flat Top Small Block Mopar Forged Piston Set 4.100 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
350 Small Block Mopar, FX, Comp Height: 1.802, -3cc Flat Top , PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-10.74, 64cc-10.47, 72cc-9.58 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6303-4040 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.040 inch bore Pin Dia.: 0.984 6303-4040 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.040 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
339 Small Block Mopar, FX, Comp Height: 1.802, -16cc Dish Top, PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-9.04, 64cc-8.86, 72cc-8.21 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6303-4070 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.070 inch bore Pin Dia.: 0.984 6303-4070 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.070 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
345 Small Block Mopar, FX, Comp Height: 1.802, -16cc Dish Top, PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-9.17, 64cc-8.99, 72cc-8.32 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6303-4080 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.080 inch bore Pin Dia.: 0.984 6303-4080 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.080 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
346 Small Block Mopar, FX, Comp Height: 1.802, -16cc Dish Top, PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-9.19, 64cc-9.01, 72cc-8.34 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options
6303-4100 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.100 inch bore Pin Dia.: 0.984 6303-4100 340 Small Block Mopar FX Series -16cc Dish Top Small Block Mopar Forged Piston Set 4.100 inch bore Pin Dia.: 0.984
from $749.95
from $749.95
350 Small Block Mopar, FX, Comp Height: 1.802, -16cc Dish Top, PIN: .984", Full-Floating or Press Fit, Ring Groove: 1.2/1.2/3MM, Stroke: 3.310", ROD: 6.123, Approx Comp Ratio: 62cc-9.27, 64cc-9.09, 72cc-8.42 Effective June 15th 2026, These Sm These Block Mopar ring grooves have been updated to the new specifications of 1.2-1.2-3mm. Parts manufactured prior to this date feature ring grooves with dimensions of 1/16-1/16-3/16.
Choose Options