74 Gold Duster and tons of questions

also, the 318 and 340 have the same 3.31" stroke crank, but the 340 has a much bigger bore at 4.04" vs. 3.91". in other words, the 318 and the 340 use essentially the same crankshaft. the 360 has a 3.58" stroke and 4.00" bore, this is why with the 4" stroker crankshaft, the 340 yields more cubic inches than the 360(if both are bored .030" over, 408" and 416")