Mopar Action On-line – Tech Questions
Gary Angell, Mason City, IA , 1968 Dodge Dart 446
How much can I bore a 1972 casting 413
It is a HD block with cast-in water pump bosses in the rear of the blockand extra heavy braces on the sides.
Can it be bored out to 440 spec. safley?
Unlikely. But, really, the only sure way to answer this is via a sonic wallthickness check. You’d like at least 0.090″ (major thrust side) at yourfinal bore size. But remember the axiom: thick cylinder walls make for agood ring seal. And a good ring seal makes power – and durability. I’ll takebeefy cylinder walls over another 10 C.I.D. any day of the week!