Distributor Differences

I have a Autolite IAT4009A and a IAT4009B distributor.   Can someone tell me what the differences may be?   I have searched the forum and literature and cannot any info. regarding the differences.   Thanks for your help.   Tom

Comments

  • The "B" distributor is for 262 and 308 engines, and has less advance curve than the "A", which is for 232 engines.   Probably has stronger springs on the flyweights.   
  • Geoff,  Thank You for the explanation.   The car originally came with the IAT4009A distributor, It never seemed to run right when hot and would periodically experience 'Pinging'.   I am rebuilding the IAT4009B distributor and will be installing it after I order a refurbished vacuum advance from Wildrick.   Thanks again, Tom
  • IAT 4009 was a distributor for the 51-2 Pacemaker only.  IAT 4009A was for the 51 model line excepting Pacemaker. The IAT 4009B was for 52-4 Wasp( 262),  Commodore and Hornet line. IAT 4203 was for the 53-4 Wasp(232)  
  • Lance,  Thanks for the extended clarification.   Tom
  • My pleasure.