Mopar Action On-line – Tech Questions
Jeff vercelli, turlock, CA, 1968 dodge sports coupe 340?
I’m trying to find out the difference between a 318 and a340 just by looking at the motors. Does one have the spark plugs slanting acertain way or not, or is there another way just by looking that defines thedifference?
At a quick glance, they are externally identical, with the sole exception ofthe left-side engine mount ears – which typically aren’t easy to see withthe engine installed. Of course, 340’s have lots of different numbers(engine numbers, head and block casting numbers, etc.) and larger intakemanifold runners (but manifolds can be swapped!)
The basic answer: unlike 383/400 to 413/440s, you really need to look atnumbers.