TC flex plate

99.999999999999999999999999999999999 per cent chance that the 318 and 340 have the same number of crank bolts....6 ....
Yup, 6 crank bolts for sure, but some cranks have an even bolt pattern, some have a UNEVEN bolt pattern. See attached pdf. file. Pdf file shows the 4 flex plates Chrysler used. Always had to ask only two questions when someone wanted a flex plate, size and bolt pattern.