building a northstare 4.6 ,bad crankshaft.Casting #12554681,all supply house,s tell me that casting#3544669 will work,witch I have but the trigger fire wheel is different and thats a problum with me ,I know how sensers work and thats a long way back apart if it wount run or run right.Thanks for any help with this,just doint know .Am a transmission builder 35 years,if I can return the faver just ask Thanks Tim