An answer from Wayne Greafen: At least on the 1958 Chrysler 300D EFI cars the primary exhaust pipe (and rest of the system) is NOT the same as the standard 300 or New Yorker. The EFI option coded cars included, as part of the package, the low restriction exhaust manifolds and the 2.5" pipes all the way out on the hardtops. These would not have been employed on a EFI convertible where the 2.5" system does not have adequate clearance in the X-member frame. What were the low restriction manifolds? They were the truck style 4-bolt flange manifolds that the factory had madified in 1957 to fit the new torsion bar chassis to gain clearance at the steering box and at the upper right control arm. I reproduced these manifolds for the '57-58 392s. I do not know if there was any change in DeSoto or Dodge EFI exhaust manifolding or exhaust system but do not believe so. Wayne Ray in Mena On May 29, 2010, at 1:25 AM, Richard Barber wrote: An interesting question from the Forward Look server: Date: Fri, 28 May 2010 11:11:55 -0400 From: DOLORES ECKERSON <eddee@xxxxxxxxxxxxx> Subject: CURIOSITY QUESTION ON FI 1958 CARS HELLO MEMBERS, and a happy Memorial Day Weekend Concerning the parts book and the 58 FUEL INJECTED cars........................ WHY would the FI cars have a separate P/N for the primary exhaust pipe from the exhaust manifolds????????????????????????? The LENGTH is the same for the CARBURETED cars The diameter must be the same because the secondary exhaust pipes are all the same. ANY IDEAS ED ECKERSON LI NY Rich Barber Brentwood, CA [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/