crankshaft help

in my 340 that broke it used to be an old 340 steel crank.. ull identify it with smaller/narrower notch from the casting.. along the counter weights.. problem i had was that it had a small pilot hole for the converter.. i had to machine down the tap on the converter. next time i rebuilt the engine i replaced the crank with a std 318.. (didnt replace rods, damper) i was told that only the 360 was external balance.. its not true, only the old pre 72 340 was all internaly balanced. they had slightly heavyer rods.. this made my engine vibrate. had to reedo all the worke.. if u use a 318 crank, be sure to change damper and rods to :) .. later 1 rod broke and ihad to weld back the nr 2 skirt on the block... after that a valve broke off and mostly all of the old 340 block is broken.. but the cast 318 crank is still perfectly fine..

the 273 forged steel crank was replaced with a standard nodular cast iron crankshaft to save money. 1969.

here are some info on the subject http://www.allpar.com/mopar/318.html :cheers: